Adarq.org
Performance Area => Peer Reviewed Studies Discussion => Topic started by: adarqui on June 12, 2009, 12:11:13 am
-
Post anything related to true plyometrics.
1. Does plyometric training improve vertical jump height? A meta-analytical review
PT provides a statistically significant and practically relevant improvement in vertical jump height with the mean effect ranging from 4.7% (SJ and DJ), over 7.5% (CMJA) to 8.7% (CMJ). These results justify the application of PT for the purpose of development of vertical jump performance in healthy individuals.
2. A Comparison of Plyometric Training Techniques for Improving Vertical Jump Ability and Energy Production
The 12-week program
resulted in significant increases in vertical jump height
for both training groups. The depth jump group
significantly improved their vertical jump height in all 3
jumps. None of the training methods improved
utilization of elastic energy. In activities involving
dynamic stretch-shorten cycles, drop jump training was
superior to countermovement jump training due to
neuromuscular specificity. This study provides support
for the strength and conditioning professional to include
plyometric depth jump training as part of the athlete's
overall program for improving vertical jumping ability
and concentric contractile performance.
3. The Influence of Varied Rest Interval Lengths on Depth Jump Performance
After determining their op-
timal depth jump height, the subjects performed 3 sets of 10
depth jumps, each set with a different rest interval duration.
The 3 rest intervals between depth jumps were 15, 30, and
60 seconds and were counterbalanced for each subject. Max-
imal vertical jump height and vertical ground reaction forces
were calculated for each depth jump trial. The Peak Perfor-
mance Motion Measurement System was used to measure
vertical jump height and the Kistler force platform was used
to measure ground reaction forces. Two-way analyses of var-
iance revealed that rest interval length did not affect (p
0.05) vertical jump height or vertical ground reaction forces.
Therefore, this study demonstrated a 15-second rest interval
was sufficient for recovery during the performance of depth
jumps.
4. The optimal training load for the development of dynamic athletic performance.
The experimental group which trained with the load that maximized mechanical power achieved the best overall results in enhancing dynamic athletic performance recording statistically significant (P < 0.05) improvements on most test items and producing statistically superior results to the two other training modalities on the jumping and isokinetic tests.
5. Drop jumping. II. The influence of dropping height on the biomechanics of drop jumping.
The results of a biomechanical analysis show no difference between DJ20 and DJ40 in mechanical output about the joints during the push-off phase. Peak values of moment and power output about the ankles during the push-off phase were found to be smaller in DJ60 than in DJ40 (DJ20 = DJ60). The amplitude of joint reaction forces increased with dropping height. During DJ60, the net joint reaction forces showed a sharp peak on the instant that the heels came down on the ground. Based on the results, researchers are advised to limit dropping height to 20 or 40 cm when investigating training effects of the execution of bounce drop jumps.
6. A Biomechanical Analysis of the Vertical Jump and Three Modified Plyometric Depth Jumps.
Maximum moment and power values were calculated for each joint. ANOVAs were used to compare the selected variables from DJ to the corresponding variables in CMJ. All variables from the selected joints were greater with DJ, and 29 of the 33 comparisons were significantly different (p <= 0.05). The corresponding joint moments for ankle, knee, and hip depth jumps were significantly greater than for CMJ. The modified plyometric jumps were shown to enhance the contribution of the muscles that extend the ankle, knee, and hip.
7. Muscle Power and Fiber Characteristics Following 8 Weeks of Plyometric Training
Peak muscle power output, measured using a countermovement vertical jump, significantly increased from pretraining to posttraining for group 1 (PLYOMETRIC TRAINING) (2.8%) and group 2 (PLYOMETRIC + AEROBIC TRAINING) (2.5%). Each group demonstrated a significant increase in fiber area from pretraining to posttraining for type I (group 1, 4.4%; group 2, 6.1%) and type II (group 1, 7.8%; group 2, 6.8%) fibers, but there were no differences between the groups. Following plyometric training, there is an increased power output that may in part be related to muscle fiber size.
8. The effect of plyometric training on distance running performance
Following the training period, the E group (PLYOMETRICALLY TRAINED) significantly improved 3-km performance (2.7%) and RE at each of the tested velocities, while no changes in V?O2max or Thla were recorded. CMJ height, 5BT, and MTS also increased significantly. No significant changes were observed in any measures for the C group. The results clearly demonstrated that a 6-week plyometric programme led to improvements in 3-km running performance. It is postulated that the increase in MTS resulted in improved RE. We speculate that the improved RE led to changes in 3-km running performance, as there were no corresponding alterations in V?O2max or Thla.
9. Comparison of Dynamic Push-Up Training and Plyometric Push-Up Training on Upper-Body Power and Strength
The PPU (PLYOMETRIC PUSHUP)
group experienced significantly greater improvements than
the DPU (DYNAMIC PUSHUP) group on the medicine ball put (p
0.03). There
was no significant difference between groups for the chest
press, although the PPU group experienced greater increases
10. EFFICACY OF A MINI-TRAMPOLINE PROGRAM FOR IMPROVING
THE VERTICAL JUMP
The mini-trampoline appears to be an effective apparatus for
increasing the height of the vertical jump. Also, the mini-trampoline
seems to elicit better technique from many individuals: In terms of
balance, there was significantly less forward translation in the jump.
Range of motion, as indicated by knee flexion in the crouch, decreased
for most subjects. And the coordination of the thigh and shank was
relatively simultaneous after the training program.
11. The effects of plyometric, weight and plyometric-weight training on anaerobic power and muscular strength
The results showed that all the training treatments elicited significant (P<0.05) improvement in all of the tested variables. However, the combination training group showed signs of improvement in the vertical jump performance, the 50 yard dash, and leg strength that was significantly greater than the improvement in the other 2 training groups (plyometric training and weight training). This study provides support for the use of a combination of traditional weight training and plyometric drills to improve the vertical jumping ability, explosive performance in general and leg strength.
12. Biomechanical analysis of drop and countermovement jumps
The results obtained for DJ appeared to depend on jumping style. In a subgroup of subjects making a movement of large amplitude (i. e. bending their hips and knees considerably before pushing off) the push-off phase of DJ closely resembled that of CMJ. In a subgroup of subjects making a movement of small amplitude, however, the duration of the push-off phase was shorter, values for moments and mean power output at the knees and ankles were larger, and the mean EMG activity of m. gastrocnemius was higher in DJ than in CMJ. The findings are attributed to the influences of the rapid pre-stretch of knee extensors and plantar flexors after touch-down in DJ. In both subgroups, larger peak resultant reaction forces were found at the knee and ankle joints, and larger peak forces were calculated for the Achilles tendon in DJ than in CMJ.
13. THE EFFECT OF PLYOMETRIC TRAINING ON STRENGTH-SPEED ABILITIES OF BASKETBALL PLAYERS
The results show a statistically significant increase in the basic mechanical parameters: the height of rise of body mass centre (Hmax) – 0.425±0.054m (I) and 0.464±0.047 m (II) (p<0.01), maximum jump velocity (Vmax)
– 2.829±0.185 m/s (I) and 2.979±0.160 m/s (II) (p<0.01), maximum force
– 1336.9±266.1 N (I) and 1437.5±213.8 N (II) (p<0.01), impulse of force (PF)
– 251.1±31.4 N•s (I) and 268.3±22.7 N•s (II) (p<0.01), maximum power
– 2814.4±615.4 W (I) and 2957.8± 579.8 W (II) (p<0.01), maximum relative
power – 32.6±5.4 W/kg (I) and 34.9±5.1 W/kg (II) (p<0.01), average power
– 1499.6±356.9 W (I) and 1624.4±329.5 W/kg (II) (p<0.01), relative average
power – 17.4±3.2 W/kg (I) and 19.2±3.0 W/kg (II) (p<0.01). No change was
observed in the take-off time – Tto (s), or countermovement depth – Gde (m).
Conclusions. The 8-week basketball training, including the plyometric training, resulted in considerable improvement in the mechanical parameters of the strengthspeed abilities of the players.
14. Does plyometric training improve vertical jump height? A meta-analytical review
The pooled estimate of the effect of PT on vertical jump height was 4.7% (95% CI 1.8 to 7.6%), 8.7% (95% CI 7.0 to 10.4%), 7.5% (95% CI 4.2 to 10.8%) and 4.7% (95% CI 0.8 to 8.6%) for the SJ, CMJ, CMJA and DJ, respectively. When expressed in standardised units (ie, effect sizes), the effect of PT on vertical jump height was 0.44 (95% CI 0.15 to 0.72), 0.88 (95% CI 0.64 to 1.11), 0.74 (95% CI 0.47 to 1.02) and 0.62 (95% CI 0.18 to 1.05) for the SJ, CMJ, CMJA and DJ, respectively. PT provides a statistically significant and practically relevant improvement in vertical jump height with the mean effect ranging from 4.7% (SJ and DJ), over 7.5% (CMJA) to 8.7% (CMJ). These results justify the application of PT for the purpose of development of vertical jump performance in healthy individuals.
15. The effect of two plyometric training techniques on muscular power and agility in youth soccer players.
Posttraining, both groups experienced improvements in vertical jump height (p < 0.05) and agility time (p < 0.05) and no change in sprint performance (p > 0.05). There were no differences between the treatment groups (p > 0.05). The study concludes that both DJ and CMJ plyometrics are worthwhile training activities for improving power and agility in youth soccer players.
16. Aquatic Plyometric Training Increases Vertical Jump in Female Volleyball Players.
Similar increases in VJ were observed in both groups after 4 wk (APT = 3.1%, CON = 4.9%; both P < 0.05); however, the APT (AQUATIC PLYOMETRIC TRAINING) group improved by an additional 8% (P < 0.05) from week 4 to week 6, whereas there was no further improvement in the CON group (-0.9%; P = NS). After 6 wk, both groups displayed significant improvements in concentric peak torque during knee extension and flexion at 60 and 180[degrees][middle dot]s-1 (all P < 0.05).
17. Kinematic Responses to Plyometric Exercises Conducted on Compliant and Noncompliant Surfaces
This study examined the effects of performing 2 different plyometric exercises, depth jump (DJ) and counter movement jump (CMJ), on noncompliant (ground) and compliant (mini-trampoline) surfaces. Male participants (N = 20; age = 21.8 ± 3.8 years; height = 184.6 ± 7.6 cm; mass = 83.6 ± 8.2 kg) randomly performed 10 CMJ and 10 DJ on compliant and noncompliant surfaces. Kinematic data were determined via 2-dimensional high-speed video. There were significant (p < 0.05) differences in DJ and CMJ joint and segment range of movement for ankle, knee, hip and trunk, indicating less crouch when the participants performed plyometric exercises on the compliant surface.
18. Effects of a plyometric program on vertical landing force and jumping performance in college women
Although not statistically significant, the mean absolute reduction in vertical ground reaction force in the training group is clinically meaningful. Eight of the 10 women in the training group reduced vertical ground reaction force by 17–18%; however, improvements in jumping performance were not observed. This indicates that programs aimed at enhancing performance must be designed differently from those aimed at reducing landing forces in recreationally athletic women.
19. Relationships between three potentiation effects of plyometric training and performance
Conclusions: Plyometric training specifically potentiated the normalized EMG, tendon stiffness and elastic energy utilization in the myotendinous complex of the triceps surae. Although these changes are possibly essential determinants, only increases of tendon stiffness were observed to correlate with performance improvements.
20. THE EFFECTS OF A 6-WEEK PLYOMETRIC TRAINING PROGRAM ON AGILITY
The plyometric training group reduced time on the ground on the posttest compared to the control group. The results of this study show that plyometric training can be an effective training technique to improve an athlete’s agility
21. THE EFFECT OF SHORT-TERM SQUAT VS DEPTH JUMP TRAINING ON VERTICAL JUMP
The primary results of this experiment indicate that vertical jump was not significantly improved with short-term plyometric or squat training using the design and volume in this study. However, a six-week periodized squat training program did increase 1RM strength. Strength coaches may have to design programs with greater volume or longer duration to elicit significant improvements in vertical jump.
22. Quantifying Plyometric Intensity via Rate of Force Development, Knee Joint, and Ground Reaction Forces
Results indicate that there are quantitative differences between plyometric exercises in the rate of force development during landing and the forces placed on the knee, though peak GRF forces associated with landing may not differ.
23. Comparative Effect of Three Modes of Plyometric Training on Leg Muscle Strength of University Male Students
Based on the findings, it was concluded that plyometrics exercises with depth jumping and rebound jumping characteristics are best used in developing muscle strength of the lower extremities.
24. Correlational Effects Of Plyometric Training On Leg Muscle Strength, Endurance And Power Characteristics Of Nigerian University Undergraduates
Correlation between all other variables was found not to be significant. Based on the finding of the study it was concluded that plyometrics training with repeated jumps horizontally and that which involves rebound jumping on the spot, are capable of improving leg muscle power in similar ways. Moreover, the study also concluded that, plyometrics training is capable of improving leg muscle strength and power significantly
25. The Effect of Drop Jump Starting Height and Contact Time on Power, Work Performed, and Moment of Force
The instructions given to the subjects were (a) “jump as high as you can” and (b) “jump high a little faster than your previous jump.” Jumps were performed at each height until the athlete could not achieve a shorter ground contact time. The data were divided into 5 groups where group 1 was made up of the longest ground contact times of each athlete and groups 2–4 were composed of progressively shorter contact times, with group 5 having the shortest contact times. The jumps of group 3 produced the highest maximum and mean mechanical power (p <0.05) during the positive phase of the drop jumps regardless of starting jump height. The vertical takeoff velocities for the first 3 groups did not show significant (p < 0.05) differences. These results indicate that the manipulation of jump technique plays larger role than jump height in the manipulation of important jump parameters.
26. A Multi-Test Assessment of Anaerobic Power in Male Athletes: Implications for Sport Specific Testing
The assessment of sport specific anaerobic power using various field and laboratory tests is often used to chart training progress and identify talent. PURPOSE: To determine if an extensive battery of anaerobic tests could successfully identify differing components of athletic power, predict short sprint performance, and distinguish between worst, average, and best performances. METHODS: 18 male college athletes (23 ± 7 yrs, Height 179 ± 5 cm, Body mass 85 ± 12 kg) performed 8 subclasses of tests to assess specific components of anaerobic power (1RM tests: Smith machine back squat, supine bench press, and barbell power clean; Jump tests: CMVJ, CMVJ + 20kg, CMVJ +40 kg, CONJ, 30cm depth jump, plyometric push up, and standing long jump; 10M sprint, 35M sprint; 10 second Quebec cycle test; 7.2kg overhead shot throw, 3.5kg seated shot throw). RESULTS: T-tests were used to assess any statistical differences between jump variables (Height (cm), Ppower (W), Ppower/kg (W/kg)) for the different jump conditions (CMVJ, CMVJ +20kg, CMVJ + 40kg, CONJ, 30cm depth jump). Correlation coefficients (r) and coefficients of determination (R squared) values were calculated between all test variables to assess commonality between tests. Correlations ranged from r = -0.85 (CD 72.4%) to r = 0.91 (CD 83%) Power produced during the depth jump condition was statistically greater (p ? 0.05) compared to all other jump conditions. Measure's corrected for body mass (Ppower/kg) produced stronger correlations when body mass was the primary resistance, and when maximal speed (10 m, 35 m sprints (s)), and height (CMVJ, CONJ) were the performance objectives. Regression analysis highlighted statistically significant groupings of variables, which could in part predict performance (10m sprint, 35m sprint (s), height CMVJ, CONJ (cm), Overhead shot distance (m), Plyopush up power (W)) outcomes. The best three groupings accounted for 65% to 85% of the performance outcomes during the performance tests. CONCLUSIONS: A combined multi-test approach of anerobic power is needed to assess varying force/velocity components of short sprint, jumping, and throwing performance with a greater degree of specificity. Care needs to be taken so that tests do not measure the same components of anaerobic power.
27. Calcium Sensitivity of Human Single Muscle Fibers following Plyometric Training.
Conclusion: Plyometric training increased single-fiber Ca2+ sensitivity, especially in type I fibers. These changes could not be explained by a modified TnT isoform expression pattern.
28. Use of an Overhead Goal Alters Vertical Jump Performance and Biomechanics
These results indicate that overhead goals may be incorporated during training and testing protocols to alter lower-extremity biomechanics and can increase performance.
-
Does plyometric training improve vertical jump height? A meta-analytical review
The aim of this study was to determine the precise effect of plyometric training (PT) on vertical jump height in healthy individuals. Meta-analyses of randomised and non-randomised controlled trials that evaluated the effect of PT on four typical vertical jump height tests were carried out: squat jump (SJ); countermovement jump (CMJ); countermovement jump with the arm swing (CMJA); and drop jump (DJ). Studies were identified by computerised and manual searches of the literature. Data on changes in jump height for the plyometric and control groups were extracted and statistically pooled in a meta-analysis, separately for each type of jump. A total of 26 studies yielding 13 data points for SJ, 19 data points for CMJ, 14 data points for CMJA and 7 data points for DJ met the initial inclusion criteria. The pooled estimate of the effect of PT on vertical jump height was 4.7% (95% CI 1.8 to 7.6%), 8.7% (95% CI 7.0 to 10.4%), 7.5% (95% CI 4.2 to 10.8%) and 4.7% (95% CI 0.8 to 8.6%) for the SJ, CMJ, CMJA and DJ, respectively. When expressed in standardised units (ie, effect sizes), the effect of PT on vertical jump height was 0.44 (95% CI 0.15 to 0.72), 0.88 (95% CI 0.64 to 1.11), 0.74 (95% CI 0.47 to 1.02) and 0.62 (95% CI 0.18 to 1.05) for the SJ, CMJ, CMJA and DJ, respectively. PT provides a statistically significant and practically relevant improvement in vertical jump height with the mean effect ranging from 4.7% (SJ and DJ), over 7.5% (CMJA) to 8.7% (CMJ). These results justify the application of PT for the purpose of development of vertical jump performance in healthy individuals.
Journal of Strength and Conditioning Research, 1998, 12(2), 85-89
A Comparison of Plyometric Training Techniques for Improving Vertical Jump Ability and Energy Production
This study was done to determine which plyometric
training technique is best for improving vertical jumping
ability, positive energy production, and elastic energy
utilization. Data were collected before and after 12
weeks of jump training and were analyzed by ANOVA.
Subjects (N = 28) performed jumps under 3 testing
conditions-squat jump, countermovement jump, and
depth jump-and were randomly assigned to 1 of 3
groups:
control,
depth
jump
training,
or
countermovement jump training. The 12-week program
resulted in significant increases in vertical jump height
for both training groups. The depth jump group
significantly improved their vertical jump height in all 3
jumps. None of the training methods improved
utilization of elastic energy. In activities involving
dynamic stretch-shorten cycles, drop jump training was
superior to countermovement jump training due to
neuromuscular specificity. This study provides support
for the strength and conditioning professional to include
plyometric depth jump training as part of the athlete's
overall program for improving vertical jumping ability
and concentric contractile performance.
The Influence of Varied Rest Interval Lengths on Depth Jump Performance
The purpose of this study was to measure the effects of var-
ied rest interval lengths on the vertical jump heights and
ground reaction forces during the execution of a depth jump
from a predetermined optimal height. The subjects were 12
men with a mean (SD) age of 25.08
2.43 years. Each sub-
ject’s optimal depth jump height was determined by execut-
ing depth jumps from 10–80 cm. After determining their op-
timal depth jump height, the subjects performed 3 sets of 10
depth jumps, each set with a different rest interval duration.
The 3 rest intervals between depth jumps were 15, 30, and
60 seconds and were counterbalanced for each subject. Max-
imal vertical jump height and vertical ground reaction forces
were calculated for each depth jump trial. The Peak Perfor-
mance Motion Measurement System was used to measure
vertical jump height and the Kistler force platform was used
to measure ground reaction forces. Two-way analyses of var-
iance revealed that rest interval length did not affect (p
0.05) vertical jump height or vertical ground reaction forces.
Therefore, this study demonstrated a 15-second rest interval
was sufficient for recovery during the performance of depth
jumps.
The optimal training load for the development of dynamic athletic performance.
APPLIED SCIENCES
Medicine & Science in Sports & Exercise. 25(11):1279-1286, November 1993.
WILSON, GREG J.; NEWTON, ROBERT U.; MURPHY, ARON J.; HUMPHRIES, BRENDAN J.
Abstract:
This study was performed to determine which of three theoretically optimal resistance training modalities resulted in the greatest enhancement in the performance of a series of dynamic athletic activities. The three training modalities included 1) traditional weight training, 2) plyometric training, and 3) explosive weight training at the load that maximized mechanical power output. Sixty-four previously trained subjects were randomly allocated to four groups that included the above three training modalities and a control group. The experimental groups trained for 10 wk performing either heavy squat lifts, depth jumps, or weighted squat jumps. All subjects were tested prior to training, after 5 wk of training and at the completion of the training period. The test items included 1) 30-m sprint, 2) vertical jumps performed with and without a countermovement, 3) maximal cycle test, 4) isokinetic leg extension test, and 5) a maximal isometric test. The experimental group which trained with the load that maximized mechanical power achieved the best overall results in enhancing dynamic athletic performance recording statistically significant (P < 0.05) improvements on most test items and producing statistically superior results to the two other training modalities on the jumping and isokinetic tests.
Drop jumping. II. The influence of dropping height on the biomechanics of drop jumping.
ORIGINAL INVESTIGATIONS
Medicine & Science in Sports & Exercise. 19(4):339-346, August 1987.
BOBBERT, MAARTEN F.; HUIJING, PETER A.; VAN INGEN SCHENAU, GERRIT JAN
Abstract:
BOBBERT, M. F., P. A. HUIJING, and G. J. VAN INGEN SCHENAU. Drop jumping. II. The influence of dropping height on the biomechanics of drop jumping. Med. Sci. Sports Exerc., Vol. 19, No. 4, pp. 339-346, 1987. In the literature, athletes preparing for explosive activities are recommended to include drop jumping in their training programs. For the execution of drop jumps, different techniques and different dropping heights can be used. This study was designed to investigate for the performance of bounce drop jumps the influence of dropping height on the biomechanics of the jumps. Six subjects executed bounce drop jumps from heights of 20 cm (designated here as DJ20), 40 cm (designated here as DJ40), and 60 cm (designated here as DJ60). During jumping, they were filmed, and ground reaction forces were recorded.
The results of a biomechanical analysis show no difference between DJ20 and DJ40 in mechanical output about the joints during the push-off phase. Peak values of moment and power output about the ankles during the push-off phase were found to be smaller in DJ60 than in DJ40 (DJ20 = DJ60). The amplitude of joint reaction forces increased with dropping height. During DJ60, the net joint reaction forces showed a sharp peak on the instant that the heels came down on the ground. Based on the results, researchers are advised to limit dropping height to 20 or 40 cm when investigating training effects of the execution of bounce drop jumps.
A Biomechanical Analysis of the Vertical Jump and Three Modified Plyometric Depth Jumps.
Article
Journal of Strength & Conditioning Research. 10(2):83-88, May 1996.
Holcomb, William R. 1; Lander, Jeffrey E. 2; Rutland, Rodney M. 3; Wilson, G. Dennis 3
Abstract:
Plyometrics are recommended for increasing strength and power. The plyometric depth jump (DJ involves the hip extensors far less than the countermovement jump (CM), thus DJ may not adequately train the hip extensors. This research sought to develop a DJ that would demand more from the hip extensors. Specific jumps were also developed for the ankle and knee extensors. Subjects, 11 college-age men, performed CMJ and DJ from a height of 50 cm. Data were collected to determine net joint moments, power, and work about the joints. Variables were calculated during the down and up phases and for the entire jump. Maximum moment and power values were calculated for each joint. ANOVAs were used to compare the selected variables from DJ to the corresponding variables in CMJ. All variables from the selected joints were greater with DJ, and 29 of the 33 comparisons were significantly different (p <= 0.05). The corresponding joint moments for ankle, knee, and hip depth jumps were significantly greater than for CMJ. The modified plyometric jumps were shown to enhance the contribution of the muscles that extend the ankle, knee, and hip.
Muscle Power and Fiber Characteristics Following 8 Weeks of Plyometric Training
We examined changes in muscle power output and fiber characteristics following a 3 d·wk?1, 8-week plyometric and aerobic exercise program. Male subjects (n = 19) were randomly assigned to either group 1 (plyometric training) or group 2 (plyometric training and aerobic exercise). The plyometric training consisted of vertical jumping, bounding, and depth jumping. Aerobic exercise (at 70% maximum heart rate) was performed for 20 minutes immediately following the plyometric workouts. Muscle biopsy specimens were collected from the musculus vastus lateralis before and after training. Type I and type II fibers were identified and cross-sectional areas calculated. Peak muscle power output, measured using a countermovement vertical jump, significantly increased from pretraining to posttraining for group 1 (2.8%) and group 2 (2.5%). Each group demonstrated a significant increase in fiber area from pretraining to posttraining for type I (group 1, 4.4%; group 2, 6.1%) and type II (group 1, 7.8%; group 2, 6.8%) fibers, but there were no differences between the groups. Following plyometric training, there is an increased power output that may in part be related to muscle fiber size.
The effect of plyometric training on distance running performance
Previous research has reported that plyometric training improves running economy (RE) and ultimately distance-running performance, although the exact mechanism by which this occurs remains unclear. This study examined whether changes in running performance resulting from plyometric training were related to alterations in lower leg musculotendinous stiffness (MTS). Seventeen male runners were pre- and post-tested for lower leg MTS, maximum isometric force, rate of force development, 5-bound distance test (5BT), counter movement jump (CMJ) height , RE, V?O2max, lactate threshold (Thla), and 3-km time. Subjects were randomly split into an experimental (E) group which completed 6 weeks of plyometric training in conjunction with their normal running training, and a control (C) group which trained as normal. Following the training period, the E group significantly improved 3-km performance (2.7%) and RE at each of the tested velocities, while no changes in V?O2max or Thla were recorded. CMJ height, 5BT, and MTS also increased significantly. No significant changes were observed in any measures for the C group. The results clearly demonstrated that a 6-week plyometric programme led to improvements in 3-km running performance. It is postulated that the increase in MTS resulted in improved RE. We speculate that the improved RE led to changes in 3-km running performance, as there were no corresponding alterations in V?O2max or Thla.
Comparison of Dynamic Push-Up Training and Plyometric Push-Up Training on Upper-Body Power and Strength
The purpose of this study was to compare dynamic push-
up (DPU) and plyometric push-up (PPU) training programs
on 2 criterion measures: (a) the distance achieved on a sit-
ting, 2-handed medicine ball put, and (b) the maximum
weight for 1 repetition of a sitting, 2-handed chest press.
Thirty-five healthy women completed 18 training sessions
over a 6-week period, with training time and repetitions
matched for the DPU (n
17) and PPU (n
18) groups.
Dynamic push-ups were completed from the knees, using a
2-second-up–2-second-down cadence. Plyometric push-ups
were also completed from the knees, with the subjects allow-
ing themselves to fall forward onto their hands and then
propelling themselves upward and back to the starting po-
sition, with 1 push-up completed every 4 seconds. The PPU
group experienced significantly greater improvements than
the DPU group on the medicine ball put (p
0.03). There
was no significant difference between groups for the chest
press, although the PPU group experienced greater increases
EFFICACY OF A MINI-TRAMPOLINE PROGRAM FOR IMPROVING
THE VERTICAL JUMP
Andrea L. Ross and Jackie L. Hudson
California State University, Chico, CA USA
The mean increase of 3.3
cm in jump height was significant. Thus, it appears that the mini-
trampoline program was effective for increasing the height of the
jump. It is possible, however, that certain individuals may not benefit
from such a program. For example, the subject who was considered
the most skillful jumper at the outset of the study did not change jump
height, and the subject with the highest jump decreased jump height
after the training program.
CONCLUSIONS
The mini-trampoline appears to be an effective apparatus for
increasing the height of the vertical jump. Also, the mini-trampoline
seems to elicit better technique from many individuals: In terms of
balance, there was significantly less forward translation in the jump.
Range of motion, as indicated by knee flexion in the crouch, decreased
for most subjects. And the coordination of the thigh and shank was
relatively simultaneous after the training program.
The effects of plyometric, weight and plyometric-weight training on anaerobic power and muscular strength
The purpose of this study was to compare the effects of 3 different training protocols-plyometric training, weight training, and their combination on the vertical jump performance, anaerobic power and muscular strength. Based on their training, forty-eight male college students were divided into 4 groups: a plyometric training group (n=13), a weight training group (n=11) a plyometric plus weight training group (n=14), and a control group (n=10). The vertical jump, the fifty-yard run and maximal leg strength were measured before and after a six-week training period. Subjects in each of the training groups trained 2 days per week, whereas control subjects did not participate in any training activity. The data was analyzed by a 1-way analysis of variance (repeated-measures design). The results showed that all the training treatments elicited significant (P<0.05) improvement in all of the tested variables. However, the combination training group showed signs of improvement in the vertical jump performance, the 50 yard dash, and leg strength that was significantly greater than the improvement in the other 2 training groups (plyometric training and weight training). This study provides support for the use of a combination of traditional weight training and plyometric drills to improve the vertical jumping ability, explosive performance in general and leg strength.
Biomechanical analysis of drop and countermovement jumps
Summary For 13 subjects the performance of drop jumps from a height of 40 cm (DJ) and of countermovement jumps (CMJ) was analysed and compared. From force plate and cine data biomechanical variables including forces, moments, power output and amount of work done were calculated for hip, knee and ankle joints. In addition, electromyograms were recorded from five muscles in the lower extremity. The results obtained for DJ appeared to depend on jumping style. In a subgroup of subjects making a movement of large amplitude (i. e. bending their hips and knees considerably before pushing off) the push-off phase of DJ closely resembled that of CMJ. In a subgroup of subjects making a movement of small amplitude, however, the duration of the push-off phase was shorter, values for moments and mean power output at the knees and ankles were larger, and the mean EMG activity of m. gastrocnemius was higher in DJ than in CMJ. The findings are attributed to the influences of the rapid pre-stretch of knee extensors and plantar flexors after touch-down in DJ. In both subgroups, larger peak resultant reaction forces were found at the knee and ankle joints, and larger peak forces were calculated for the Achilles tendon in DJ than in CMJ.
THE EFFECT OF PLYOMETRIC TRAINING ON STRENGTH-SPEED ABILITIES OF BASKETBALL PLAYERS
Tomasz Boraczy?ski, Jerzy Urnia?
Research Yearbook 2008; 14(1):14-19
ICID: 879011
Article type: Original article
IC™ Value: 5.43
Abstract provided by Publisher
Background. The aim of the study was to assess the effect of plyometric training on the strength-speed abilities of basketball players.
Material and methods. Fourteen players from a third league team participated in two study sessions, at the beginning of the preparation period and after 8 weeks of training. Between the examinations, the players took part in 84 training sessions, among which there were 25 plyometric training sessions.
Results. Biometric characteristics of the players: age 20.3±1.9 years old, body mass 84.4±8.1 kg (I session) and 83.5±7.7 kg (II session) (p<0.01), lean body mass – 73.5±7.3 kg (I) and 73.3± 7.1 kg (II), fat mass 11.0±1.9 kg (I) and 10.1±1.6 kg (II) (p<0.01). The strength-speed abilities were assessed with a test on a force plate, consisting of 10 vertical jumps (CMJ), separated by a 6 second break. The results show a statistically significant increase in the basic mechanical parameters: the height of rise of body mass centre (Hmax) – 0.425±0.054m (I) and 0.464±0.047 m (II) (p<0.01), maximum jump velocity (Vmax)
– 2.829±0.185 m/s (I) and 2.979±0.160 m/s (II) (p<0.01), maximum force
– 1336.9±266.1 N (I) and 1437.5±213.8 N (II) (p<0.01), impulse of force (PF)
– 251.1±31.4 N•s (I) and 268.3±22.7 N•s (II) (p<0.01), maximum power
– 2814.4±615.4 W (I) and 2957.8± 579.8 W (II) (p<0.01), maximum relative
power – 32.6±5.4 W/kg (I) and 34.9±5.1 W/kg (II) (p<0.01), average power
– 1499.6±356.9 W (I) and 1624.4±329.5 W/kg (II) (p<0.01), relative average
power – 17.4±3.2 W/kg (I) and 19.2±3.0 W/kg (II) (p<0.01). No change was
observed in the take-off time – Tto (s), or countermovement depth – Gde (m).
Conclusions. The 8-week basketball training, including the plyometric training, resulted in considerable improvement in the mechanical parameters of the strengthspeed abilities of the players.
-
Does plyometric training improve vertical jump height? A meta-analytical review
ABSTRACT
The aim of this study was to determine the precise effect of plyometric training (PT) on vertical jump height in healthy individuals. Meta-analyses of randomised and non-randomised controlled trials that evaluated the effect of PT on four typical vertical jump height tests were carried out: squat jump (SJ); countermovement jump (CMJ); countermovement jump with the arm swing (CMJA); and drop jump (DJ). Studies were identified by computerised and manual searches of the literature. Data on changes in jump height for the plyometric and control groups were extracted and statistically pooled in a meta-analysis, separately for each type of jump. A total of 26 studies yielding 13 data points for SJ, 19 data points for CMJ, 14 data points for CMJA and 7 data points for DJ met the initial inclusion criteria. The pooled estimate of the effect of PT on vertical jump height was 4.7% (95% CI 1.8 to 7.6%), 8.7% (95% CI 7.0 to 10.4%), 7.5% (95% CI 4.2 to 10.8%) and 4.7% (95% CI 0.8 to 8.6%) for the SJ, CMJ, CMJA and DJ, respectively. When expressed in standardised units (ie, effect sizes), the effect of PT on vertical jump height was 0.44 (95% CI 0.15 to 0.72), 0.88 (95% CI 0.64 to 1.11), 0.74 (95% CI 0.47 to 1.02) and 0.62 (95% CI 0.18 to 1.05) for the SJ, CMJ, CMJA and DJ, respectively. PT provides a statistically significant and practically relevant improvement in vertical jump height with the mean effect ranging from 4.7% (SJ and DJ), over 7.5% (CMJA) to 8.7% (CMJ). These results justify the application of PT for the purpose of development of vertical jump performance in healthy individuals.
The effect of two plyometric training techniques on muscular power and agility in youth soccer players.
The aim of this study was to compare the effects of two plyometric training techniques on power and agility in youth soccer players. Twelve males from a semiprofessional football club's academy (age = 17.3 +/- 0.4 years, stature = 177.9 +/- 5.1 cm, mass = 68.7 +/- 5.6 kg) were randomly assigned to 6 weeks of depth jump (DJ) or countermovement jump (CMJ) training twice weekly. Participants in the DJ group performed drop jumps with instructions to minimize ground-contact time while maximizing height. Participants in the CMJ group performed jumps from a standing start position with instructions to gain maximum jump height. Posttraining, both groups experienced improvements in vertical jump height (p < 0.05) and agility time (p < 0.05) and no change in sprint performance (p > 0.05). There were no differences between the treatment groups (p > 0.05). The study concludes that both DJ and CMJ plyometrics are worthwhile training activities for improving power and agility in youth soccer players.
Aquatic Plyometric Training Increases Vertical Jump in Female Volleyball Players.
Applied Sciences
Medicine & Science in Sports & Exercise. 37(10):1814-1819, October 2005.
MARTEL, GREGORY F.; HARMER, MATTHEW L.; LOGAN, JENNIFER M.; PARKER, CHRISTOPHER B.
Abstract:
Purpose: Numerous studies have reported that land-based plyometrics can improve muscular strength, joint stability, and vertical jump (VJ) in athletes; however, due to the intense nature of plyometric training, the potential for acute muscle soreness or even musculoskeletal injury exists. Performance of aquatic plyometric training (APT) could lead to similar benefits, but with reduced risks due to the buoyancy of water. Unfortunately, there is little information regarding the efficacy of APT. Thus, the purpose of this study was to examine the effects of APT on VJ and muscular strength in volleyball players.
Methods: Nineteen female volleyball players (aged 15 +/- 1 yr) were randomly assigned to perform 6 wk of APT or flexibility exercises (CON) twice weekly, both in addition to traditional preseason volleyball training. Testing of leg strength was performed at baseline and after 6 wk, and VJ was measured at baseline and after 2, 4, and 6 wk.
Results: Similar increases in VJ were observed in both groups after 4 wk (APT = 3.1%, CON = 4.9%; both P < 0.05); however, the APT group improved by an additional 8% (P < 0.05) from week 4 to week 6, whereas there was no further improvement in the CON group (-0.9%; P = NS). After 6 wk, both groups displayed significant improvements in concentric peak torque during knee extension and flexion at 60 and 180[degrees][middle dot]s-1 (all P < 0.05).
Conclusions: The combination of APT and volleyball training resulted in larger improvements in VJ than in the CON group. Thus, given the likely reduction in muscle soreness with APT versus land-based plyometrics, APT appears to be a promising training option.
Kinematic Responses to Plyometric Exercises Conducted on Compliant and Noncompliant Surfaces
Crowther, R.G., W.L. Spinks, A.S. Leicht, and C.D. Spinks. Kinematic responses to plyometric exercises conducted on compliant and noncompliant surfaces. J. Strength Cond. Res. 21(2):460–465. 2007.—Jumping is an important performance component of many sporting activities. A number of training modalities have been used to enhance jumping performance including plyometrics. The positive effects of plyometric training on jumping performance are a function of the stretch-shortening cycle phenomenon. However, there has been little research on the effects of the surface on jumping performance. This study examined the effects of performing 2 different plyometric exercises, depth jump (DJ) and counter movement jump (CMJ), on noncompliant (ground) and compliant (mini-trampoline) surfaces. Male participants (N = 20; age = 21.8 ± 3.8 years; height = 184.6 ± 7.6 cm; mass = 83.6 ± 8.2 kg) randomly performed 10 CMJ and 10 DJ on compliant and noncompliant surfaces. Kinematic data were determined via 2-dimensional high-speed video. There were significant (p < 0.05) differences in DJ and CMJ joint and segment range of movement for ankle, knee, hip and trunk, indicating less crouch when the participants performed plyometric exercises on the compliant surface.
Effects of a plyometric program on vertical landing force and jumping performance in college women
Physical Therapy in Sport, Volume 9, Issue 4, Pages 185-192
J. Vescovi, P. Canavan, S. Hasson
Abstract
Objectives
To examine the effects of a plyometric program on peak vertical ground reaction force as well as kinetic jumping characteristics in recreationally athletic college women.
Design
Six week prospective exercise intervention.
Setting
Division I university campus.
Participants
Twenty college females who competed recreationally in basketball were randomly assigned to a training (n=10) or control (n=10) group.
Main outcome measures
The absolute change values for vertical ground reaction force, countermovement jump height, peak and average jump power, and peak jump velocity. Comparisons were made using Mann–Whitney U tests.
Results
Vertical ground reaction force decreased in the intervention group (?222.8±610.9N), but was not statistically different (p=0.122) compared to the change observed in the control group (54.6±257.6N). There was no difference in the absolute change values between groups for countermovement jump height (1.0±2.8cm vs. ?0.2±1.5cm, p=0.696) or any of the associated kinetic variables following the 6-week intervention.
Conclusions
Although not statistically significant, the mean absolute reduction in vertical ground reaction force in the training group is clinically meaningful. Eight of the 10 women in the training group reduced vertical ground reaction force by 17–18%; however, improvements in jumping performance were not observed. This indicates that programs aimed at enhancing performance must be designed differently from those aimed at reducing landing forces in recreationally athletic women.
Relationships between three potentiation effects of plyometric training and performance
This study measured the potentiation effects of plyometric training [normalized electromyography (EMG) in triceps surae, stiffness and elastic energy utilization of the Achilles tendon] and investigated the correlations between these effects and performances [voluntary electromechanical delay (EMD) and jump height]. Twenty-one subjects were randomly assigned either to the control group (10 subjects: age 22.3±1.6 years) or to a training group (11 subjects: age 22.1±1.6 years) that performed 8 weeks of plyometric training. Results: As compared with the performances before training, normalized EMG in the soleus were significantly (P?0.001) increased after 4 and 8 weeks of training. Tendon stiffness, elastic energy storage, release and jump height determined after training were significantly increased (P<0.05), with a concomitantly reduced voluntary EMD (P=0.01). These variables also showed significant differences vs the control group (all P<0.05). The other variables remained unchanged. Correlations were observed between tendon stiffness and either voluntary EMD (r=?0. 77, P=0.014) or jump height (r=0.54, P=0.031). Conclusions: Plyometric training specifically potentiated the normalized EMG, tendon stiffness and elastic energy utilization in the myotendinous complex of the triceps surae. Although these changes are possibly essential determinants, only increases of tendon stiffness were observed to correlate with performance improvements.
THE EFFECTS OF A 6-WEEK PLYOMETRIC TRAINING
PROGRAM ON AGILITY
The purpose of the study was to determine if six weeks of plyometric training can improve an athlete’s
agility. Subjects were divided into two groups, a plyometric training and a control group. The plyometric
training group performed in a six week plyometric training program and the control group did not
perform any plyometric training techniques. All subjects participated in two agility tests: T-test and
Illinois Agility Test, and a force plate test for ground reaction times both pre and post testing. Univariate
ANCOVAs were conducted to analyze the change scores (post – pre) in the independent variables by
group (training or control) with pre scores as covariates. The Univariate ANCOVA revealed a significant
group effect F
2,26
= 25.42, p=0.0000 for the T-test agility measure. For the Illinois Agility test, a
significant group effect F
2,26
= 27.24, p = 0.000 was also found. The plyometric training group had
quicker posttest times compared to the control group for the agility tests. A significant group effect F
2,26
= 7.81, p = 0.002 was found for the Force Plate test. The plyometric training group reduced time on the
ground on the posttest compared to the control group. The results of this study show that plyometric
training can be an effective training technique to improve an athlete’s agility
THE EFFECT OF SHORT-TERM SQUAT VS DEPTH JUMP TRAINING ON VERTICAL JUMP
KL Bebernes, LE Brown FACSM, JW Coburn, B Beam, SM Zinder
Human Performance Laboratory. California State University, Fullerton. Fullerton, CA
A wide variety of sports rely on training techniques to enhance an athlete’s power output. Vertical jump is a reliable way to test for power; therefore the purpose of this study was to determine the effectiveness of a short-term squat (S) training program or a depth jump (DJ) training program on vertical jump performance and one repetition maximum (1RM) strength. 30 male (n=16) and female (n=14) university students (age 24.03 ± 4.67 years, height 67.14 ± 3.38 cm, weight 169.40 ± 33.63 lb) were assigned to three groups: S, DJ or control (C). The subjects in the intervention groups participated in periodized training three days a week for a total of six weeks whereas the control group did not train. Vertical jump height, 1RM and ground reaction force (GRF) were tested before and after training and the alpha level was set at 0.05. Three way ANOVA analysis of variance results demonstrated a significant (p = 0.007) increase in 1RM for the squat group of 15.05% (pre=254 ± 73.09; post=299 ± 81.73lb). Vertical jump increased in all three groups (DJ pre=19.85 ± 4.33 to 20.75 ± 4.30; S pre=20.55 ± 4.44 to 22.2 ± 4.11; C pre=19.43 ± 4.6 to 20.5 ± 4.56) but not significantly different from one another. GRF did not change from pre to post in any group. The primary results of this experiment indicate that vertical jump was not significantly improved with short-term plyometric or squat training using the design and volume in this study. However, a six-week periodized squat training program did increase 1RM strength. Strength coaches may have to design programs with greater volume or longer duration to elicit significant improvements in vertical jump.
Quantifying Plyometric Intensity via Rate of Force Development, Knee Joint, and Ground Reaction Forces
Randall L. Jensen1, 3 and William P. Ebben2
1. Northern Michigan University, Marquette, Michigan 49855, 2. Department of Physical Therapy, Program in Exercise Science, Marquette University, Milwaukee, Wisconsin 53201, 3. Address correspondence to Dr. Randall L. Jensen, E-mail: rajensen@nmu.edu
Options:
* Create Reference
* Email this Article
* Add to MyArchive
Search Google Scholar for:
* Randall L. Jensen
* William P. Ebben
Jensen, R.L., and W.P. Ebben. Quantifying plyometric intensity via rate of force development, knee joint, and ground reaction forces. J. Strength Cond. Res. 21(3):763–767. 2007.—Because the intensity of plyometric exercises usually is based simply upon anecdotal recommendations rather than empirical evidence, this study sought to quantify a variety of these exercises based on forces placed upon the knee. Six National Collegiate Athletic Association Division I athletes who routinely trained with plyometric exercises performed depth jumps from 46 and 61 cm, a pike jump, tuck jump, single-leg jump, countermovement jump, squat jump, and a squat jump holding dumbbells equal to 30% of 1 repetition maximum (RM). Ground reaction forces obtained via an AMTI force plate and video analysis of markers placed on the left hip, knee, lateral malleolus, and fifth metatarsal were used to estimate rate of eccentric force development (E-RFD), peak ground reaction forces (GRF), ground reaction forces relative to body weight (GRF/BW), knee joint reaction forces (K-JRF), and knee joint reaction forces relative to body weight (K-JRF/BW) for each plyometric exercise. One-way repeated measures analysis of variance indicated that E-RFD, K-JRF, and K-JRF/BW were different across the conditions (p < 0.05), but peak GRF and GRF/BW were not (p > 0.05). Results indicate that there are quantitative differences between plyometric exercises in the rate of force development during landing and the forces placed on the knee, though peak GRF forces associated with landing may not differ.
Comparative Effect of Three Modes of Plyometric Training on
Leg Muscle Strength of University Male Students
Ademola Olasupo Abass
Department of Human Kinetics and Health Education
Faculty Of Education, University of Ibadan, Nigeria
E-mail: dokidemo@yahoo.com
Abstract
This study determined the comparative effect of three modes of Plyometrics
training [depth jumping, rebound jumping and horizontal jumping] on leg muscle strength
of untrained University male students. Participants were forty untrained male University
students within the age range of 18-27 years. The randomized pretest-posttest control group
design was adopted. Subjects were randomly assigned to control group, and three
experimental groups based on the types of plyometrics training adopted for the study. The
training programme consisted of twelve weeks of interval training administered three times
a week. Data collected were analyzed using the mean score, standard deviation and range.
Analysis of Covariance [ANCOVA] was used to test for significant differences in the post-
test measures among the treatment and control groups using the pretest score variation as
covariates. Scheffe post hoc analysis was used to determine which of the means were
significantly different. All hypotheses for the study were tested at 0.05 critical level.
Findings revealed that only the depth jumping and rebound jumping training
significantly altered leg muscle strength of subjects (P<0.05). Based on the findings, it was
concluded that plyometrics exercises with depth jumping and rebound jumping
characteristics are best used in developing muscle strength of the lower extremities.
Correlational Effects Of Plyometric Training On Leg Muscle Strength, Endurance
And Power Characteristics Of Nigerian University Undergraduates
Ademola O. Abass
Department of Human Kinetics And Health Education
Faculty of Education
University of Ibadan, Ibadan
Nigeria.
E-mail: dokidemo@yahoo.com
Phone: +2348055436276
Abstract
This study focused on the relationship among strength, endurance and power performance
characteristics of untrained university undergraduates following three different modes of plyometric
training. Participants were 40 untrained volunteer male undergraduates, randomly assigned to
three experimental plyometric training groups of depth jumping, rebound jumping and horizontal
jumping over a distance, and a fourth group which served as the control. The three experimental
groups were made to go through a 12-week exercise programme based on plyometric training
procedures. Interval training method was adopted while the progressive resistance training principle
was considered to determine the duration and intensity of training. Data collected were analyzed
using the mean, standard deviation and range. Relationship between variables was determined
using the Pearson Product Moment Correlation Coefficient. Results show that there were no
significant relationships among the groups in strength and endurance performance characteristics.
Significant correlations were recorded in power performance between horizontal jumping and
rebound jumping group [0.672; P= 0.033]. All other interactions among the groups on leg
power were not significant. On relationship among the three variables based on pooled data across
the groups, significant correlation was recorded only between muscle strength and power
[0.327;P= 0.039]. Correlation between all other variables was found not to be significant. Based
on the finding of the study it was concluded that plyometrics training with repeated jumps
horizontally and that which involves rebound jumping on the spot, are capable of improving leg
muscle power in similar ways. Moreover, the study also concluded that, plyometrics training is
capable of improving leg muscle strength and power significantly
The Effect of Drop Jump Starting Height and Contact Time on Power, Work Performed, and Moment of Force
Walsh, M., A. Arampatzis, F. Schade, and G.-P. Brüggemann. The effect of drop jump starting height and contact time on power, work performed, and moment of force. J. Strength Cond. Res. 18(3):561–566. 2004.—The purposes of this study are (a) to examine the effects of contact time manipulation on jump parameters and (b) to examine the interaction between starting height changes and contact time changes on important jump parameters. Fifteen male athletes performed a series of drop jumps from heights of 20, 40, and 60 cm. The instructions given to the subjects were (a) “jump as high as you can” and (b) “jump high a little faster than your previous jump.” Jumps were performed at each height until the athlete could not achieve a shorter ground contact time. The data were divided into 5 groups where group 1 was made up of the longest ground contact times of each athlete and groups 2–4 were composed of progressively shorter contact times, with group 5 having the shortest contact times. The jumps of group 3 produced the highest maximum and mean mechanical power (p <0.05) during the positive phase of the drop jumps regardless of starting jump height. The vertical takeoff velocities for the first 3 groups did not show significant (p < 0.05) differences. These results indicate that the manipulation of jump technique plays larger role than jump height in the manipulation of important jump parameters.
A Multi-Test Assessment of Anaerobic Power in Male Athletes: Implications for Sport Specific Testing.
The assessment of sport specific anaerobic power using various field and laboratory tests is often used to chart training progress and identify talent. PURPOSE: To determine if an extensive battery of anaerobic tests could successfully identify differing components of athletic power, predict short sprint performance, and distinguish between worst, average, and best performances. METHODS: 18 male college athletes (23 ± 7 yrs, Height 179 ± 5 cm, Body mass 85 ± 12 kg) performed 8 subclasses of tests to assess specific components of anaerobic power (1RM tests: Smith machine back squat, supine bench press, and barbell power clean; Jump tests: CMVJ, CMVJ + 20kg, CMVJ +40 kg, CONJ, 30cm depth jump, plyometric push up, and standing long jump; 10M sprint, 35M sprint; 10 second Quebec cycle test; 7.2kg overhead shot throw, 3.5kg seated shot throw). RESULTS: T-tests were used to assess any statistical differences between jump variables (Height (cm), Ppower (W), Ppower/kg (W/kg)) for the different jump conditions (CMVJ, CMVJ +20kg, CMVJ + 40kg, CONJ, 30cm depth jump). Correlation coefficients (r) and coefficients of determination (R squared) values were calculated between all test variables to assess commonality between tests. Correlations ranged from r = -0.85 (CD 72.4%) to r = 0.91 (CD 83%) Power produced during the depth jump condition was statistically greater (p ? 0.05) compared to all other jump conditions. Measure's corrected for body mass (Ppower/kg) produced stronger correlations when body mass was the primary resistance, and when maximal speed (10 m, 35 m sprints (s)), and height (CMVJ, CONJ) were the performance objectives. Regression analysis highlighted statistically significant groupings of variables, which could in part predict performance (10m sprint, 35m sprint (s), height CMVJ, CONJ (cm), Overhead shot distance (m), Plyopush up power (W)) outcomes. The best three groupings accounted for 65% to 85% of the performance outcomes during the performance tests. CONCLUSIONS: A combined multi-test approach of anerobic power is needed to assess varying force/velocity components of short sprint, jumping, and throwing performance with a greater degree of specificity. Care needs to be taken so that tests do not measure the same components of anaerobic power.
Calcium Sensitivity of Human Single Muscle Fibers following Plyometric Training.
BASIC SCIENCES
Medicine & Science in Sports & Exercise. 38(11):1901-1908, November 2006.
MALISOUX, LAURENT 1; FRANCAUX, MARC 1; NIELENS, HENRI 1; RENARD, PATRICIA 2; LEBACQ, JEAN 3; THEISEN, DANIEL 1
Abstract:
Purpose: To study the effect of plyometric training on Ca2+ sensitivity and the influence of troponin T (TnT) isoforms on Ca2+-activation properties in skinned human muscle fibers.
Methods: Biopsies were obtained from the vastus lateralis of eight men before and after the training period. Chemically skinned fibers were evaluated regarding their Ca2+-activation properties and were classified according to their myosin heavy chain (MHC) contents and analyzed regarding their slow and fast TnT isoforms.
Results: After training, significant improvements (P < 0.05) were found for static jump, countermovement jump, 6 x 5-m shuttle-run test, and leg-press performances. An 8% increase in the proportion of type IIa fibers (P < 0.05) was observed. Single-fiber diameters increased by 11% in type I (P < 0.01), 10% in type IIa (P < 0.001), and 15% in type IIa/IIx fibers (P < 0.001). Peak fiber force increased by 35% in type I (P < 0.001), 25% in type IIa (P < 0.001), and 57% in type IIa/IIx fibers (P < 0.01). The Ca2+-activation threshold was not altered by training, but the Ca2+ concentration required to elicit half-maximal activation showed a decreasing trend, with significant changes in type I fibers (P < 0.001). Cooperativity at low Ca2+ concentrations was increased in type I and type IIa/IIx fibers (P < 0.05). Type I fibers exclusively expressed slow TnT isoforms, and type II fibers were always associated with fast TnT isoforms, independent of training status. Therefore, changes in Ca2+ sensitivity after training could not be explained by differential fast or slow TnT isoform expression.
Conclusion: Plyometric training increased single-fiber Ca2+ sensitivity, especially in type I fibers. These changes could not be explained by a modified TnT isoform expression pattern.
The Effect of Short-Term VertiMax vs. Depth Jump Training on Vertical Jump Performance.
Original Research
Journal of Strength & Conditioning Research. 22(2):321-325, March 2008.
McClenton, LaKeysha S; Brown, Lee E; Coburn, Jared W; Kersey, Robert D
Abstract:
The ability to generate lower body explosive power is considered an important factor in many athletic activities. Thirty-one men and women, recreationally trained volunteers, were randomly assigned to 3 different groups (control, n = 10; VertiMax, n = 11; and depth jump, n = 10). A Vertec measuring device was used to test vertical jump height pre- and post-training. All subjects trained twice weekly for 6 weeks, performing approximately 140 jumps. The VertiMax group increased elastic resistance and decreased volume each week, while the depth jump group increased both box height and volume each week. The depth jump group significantly increased their vertical jump height (pre: 20.5 +/- 3.98; post: 22.65 +/- 4.09), while the VertiMax (pre: 22.18 +/- 4.31; post: 23.36 +/- 4.06) and control groups (pre: 15.65 +/- 4.51; post: 15.85 +/- 4.17) did not change. These findings suggest that, within the volume and intensity constraints of this study, depth jump training twice weekly for 6 weeks is more beneficial than VertiMax jump training for increasing vertical jump height. Strength professionals should focus on depth jump exercises in the short term over commercially available devices to improve vertical jump performance.
Use of an Overhead Goal Alters Vertical Jump Performance and Biomechanics
Kevin R. Ford1, 4, Gregory D. Myer1, Rose L. Smith2, Robyn N. Byrnes2, Sara E. Dopirak2, and Timothy E. Hewett1, 3, 2
1. Cincinnati Children's Hospital Research Foundation, Sports Medicine Biodynamics Center, and Human Performance Laboratory, Cincinnati, Ohio 45229, 2. University of Cincinnati, College of Allied Health Sciences, Physical Therapy Department, Cincinnati, Ohio, 3. University of Cincinnati, College of Medicine, Departments of Pediatrics and Orthopaedic Surgery, Cincinnati, Ohio, 4. Address correspondence to Kevin R. Ford, M.S., E-mail: Kevin.Ford@cchmc.org
Options:
* Create Reference
* Email this Article
* Add to MyArchive
Search Google Scholar for:
* Kevin R. Ford
* Gregory D. Myer
* Rose L. Smith
* Robyn N. Byrnes
* Sara E. Dopirak
* Timothy E. Hewett
Ford, K.R., G.D. Myer, R.L. Smith, R.N. Byrnes, S.E. Dopirak, and T.E. Hewett. Use of an overhead goal alters vertical jump performance and biomechanics. J. Strength Cond. Res. 19(2):394–399. 2005.—This study examined whether an extrinsic motivator, such as an overhead goal, during a plyometric jump may alter movement biomechanics. Our purpose was to examine the effects of an overhead goal on vertical jump height and lower-extremity biomechanics during a drop vertical jump and to compare the effects on female (N = 1Cool versus male (N = 17) athletes. Drop vertical jump was performed both with and without the use of an overhead goal. Greater vertical jump height (p = 0.002) and maximum takeoff external knee flexion (quadriceps) moment (p = 0.04) were attained with the overhead goal condition versus no overhead goal. Men had significantly greater vertical jump height (p < 0.001), maximum takeoff vertical force (p = 0.009), and maximum takeoff hip extensor moment (p = 0.02) compared with women. A significant gender × overhead goal interaction was found for stance time (p = 0.02) and maximum ankle (p = 0.04) and knee flexion angles (p = 0.04), with shorter stance times and lower angles in men during overhead goal time. These results indicate that overhead goals may be incorporated during training and testing protocols to alter lower-extremity biomechanics and can increase performance.
-
DIFFERENCES BETWEEN THE ELITEAND SUB-ELITE SPRINTERS INKINEMATIC AND KINETIC VARIABLESOF DROP JUMP
AbstractThe aim of the study was to examine differences in an area of take-off strength between the elite and sub-elite sprinters. Drop jump–45cm tests were used as criteria of take-off strength. Sample of measured subjects included 12 best sprinters. They divided in two sub-groups with the official 100-metre sprint running result being used as a grouping criterion. Biomechanical parameters of both jumpswere measured with the use of bipedal tensiometric platform and a system of 9 infraspectral CCD cameras with a 200 Hz frequency.Differences between the groups of sprinters were examined with the use of ANOVA variance analysis. Statistically significant (p< 0.05)differences between the sprinters of both groups were revealed in three kinematic and kinetic parameters. In drop jump, elite and sub-elite sprinters differentiated in the realisation of movement velocity in the eccentric and concentric phases (a difference between thegroups is statistically significant p< 0.05). Elite sprinters better utilise the stretch reflex, which allows them to more efficiently transferelastic energy from first into second phase of take-off action
-
Hey Andrew, I have a question for you. I know your big into depth jumping. Going through the literature it doesn't seem to be clear and I wanted to get your input on this question. Clearly the literature suggests that:
1) A program involving depth jumping AND practice of the CMJ (running or standing) yields better results than one that only includes practice of CMJ.
This seems to be well supported by the evidence. However...
Do you think that the same is true in so far as:
1) A program that involves practice of CMJ and rebound jumps (eg repeated vertical jumps to a target, repeated horizontal jumps (double leg bounding, etc)
2) The same program + depth jumping. Given that the rest intervals for depth jumps were insignificant (15sec, vs 30,60) does it not seem that depth jumps would provide a lot less advantage to a program that already involves repeated jumps (of course repeated jump spacing is far smaller (1-2 seconds) and you can't depth jump with such intervals unless you have a strange stair setup...
Interested in your thoughts. Personally, I believe depth jumps provide limited help in a program that already involves a multitude of multiple jumps.
-
Hey Andrew, I have a question for you. I know your big into depth jumping. Going through the literature it doesn't seem to be clear and I wanted to get your input on this question. Clearly the literature suggests that:
1) A program involving depth jumping AND practice of the CMJ (running or standing) yields better results than one that only includes practice of CMJ.
This seems to be well supported by the evidence. However...
Do you think that the same is true in so far as:
1) A program that involves practice of CMJ and rebound jumps (eg repeated vertical jumps to a target, repeated horizontal jumps (double leg bounding, etc)
2) The same program + depth jumping. Given that the rest intervals for depth jumps were insignificant (15sec, vs 30,60) does it not seem that depth jumps would provide a lot less advantage to a program that already involves repeated jumps (of course repeated jump spacing is far smaller (1-2 seconds) and you can't depth jump with such intervals unless you have a strange stair setup...
Interested in your thoughts. Personally, I believe depth jumps provide limited help in a program that already involves a multitude of multiple jumps.
hey T0ddday. I think DJ's would still be effective in scenario 2. But it depends on what kind of volume/box heights we're using. If we incorporate DJ's with high volume (30-40 total jumps) from a high box (30-40 inches), CMJ & rebounding jumps/bounds would need to play more of an assistance role and as part of a progressively more intense warmup/build up for max intensity depth jumps. Depth jumps in this case would become the entire focus of the session. This form of incorporating depth jumps would yield the best results IMHO, but it's also the most intense & requires far more preparation/safety precautions.
If we incorporate them at lower volume, say 5-15 (3x3, 3x5 etc) total jumps from moderate to fairly high boxes (12-30"), I think they still would provide some benefit but obviously not as much as the scenario above. Instead they would serve as "prep work" if our athletes are not too experienced with them (low boxes) and a tool for strength gain (higher boxes, 24-30"). We could just inject these into a session for the most part.
The DJ itself just represents another level of intensity, so that's why I think it could still be effective in the scenario you posted. It's a method which Verkhoshansky stated would call to action the strength reserves that are protected from conscious recruitment (special and/or innately defended). By providing the supramaximal stimulus of depth jumping from high boxes, you tap into these reserves. A quote from supermethods (dammit can't copy+paste):
So, when an athlete lifts a barbell or executes an ordinary vertical jump, the effort is entirely volitional. Everything depends on his concentrated effort and the mobilization of motor potential. If the sportsman conducts a vertical take-off after a depth jump with the aim of flying up as high as possible or runs down a slight incline at maximum speed, these conditions force his central nervous and physiological systems to exceed the ordinary boundaries. The creation of such conditions in the training process is the forced intensification of the work regime which becomes a potent training stimulus.
Apparently, under these conditions, the body mobilizes any innate mechanisms designed by nature to be available for these and even more complex, extreme situations.
- reserves employed in reactive movements (15%)
- physiological reserves employed under conditions of elevated motor activity (20%)
- special reserves mobilized only under conditions of muscle performance of great intensity or long duration (35%)
- innately defended reserves mobilized only in extreme, life-threatening situations (30%)
The special and innately defended reserves are distinguished by their mobilization barrier, inhibited by the central nervous system. Overcoming this barrier under normal living conditions is precluded by a protective inhibition, which forces the body to reduce the intensity of work, or cease it.
...
Experiments conducted in my lab demonstrated that the aforementioned "protected" functional reserves of the body are inaccessible regardless of the intensity of the volutional effort without special long-term training.
...
Consequently, it is necessary to create the training conditions that will force the body to mobilize the hidden (concealed) functional reserves and to form central-nervous system mechanisms for their application, ie. to make them accessible for mobilization from a strength-of-will impulse.
-- http://www.verkhoshansky.com/LinkClick.aspx?fileticket=bBhPjzgn%2B0A%3D&tabid=92&mid=426
So, he says you can tap into the "special reserves" through years of specialized training, which is what bounds and various jumping drills are. But, to tap into these "innately defended" reserves, you need "Super Methods", ie depth jumps or downhill sprints etc.
So, DJ in my opinion (and experience) is a much more intense tool than pretty much all of the reactive work. Incorporating it as prep work or in lower volume should provide some benefit. I've seen studies claiming benefits in a variety of protocols, but not sure if some of those studies showed benefits simply from supplementing them into an existing program full of beneficial reactive work.
Also, He never mentions single leg bounding in the same area as depth jumps, ie a super method.. if it isn't, it has to be creeping close to that spectrum though, single leg bounds are very intense.
I don't think it should be prescribed high volume + high box height in combination with lots of other work. Then I think it would actually be very detrimental & extremely risky.
On another note, i've done sessions with TONS of reactive work. Overdoing it to the max, all kinds of different varieties of things. I don't recall any of that being as intense as 4x10 depth jumps from 30". 40 total DJ's from 30" had my CNS destroyed and next-day ligaments/tendons feeling wrecked. Performing DJ's towards the second half (reps 5-10) of a set required some serious focus; it felt on the level of a max effort single in terms of how I would have to dial in. I havn't experienced that from lower volume protocols such as 3x3, 3x5 etc.
Finally.. My body is afraid of depth jumping until it's actually prepared. I can go do double leg bounds, kangaroo hops, attempt single leg bounds right now with my severe lack of prepardness.. However, if someone told me to go perform some DJ's from 30" i'd have some serious inhibition. I'd actually be afraid to do it. I could do a depth drop from 30" but I wouldn't even try a DJ from 30" right now (without prepping for several weeks). I find that interesting.
pc!!!
-
So, DJ in my opinion (and experience) is a much more intense tool than pretty much all of the reactive work. Incorporating it as prep work or in lower volume should provide some benefit. I've seen studies claiming benefits in a variety of protocols, but not sure if some of those studies showed benefits simply from supplementing them into an existing program full of beneficial reactive work.
Also, He never mentions single leg bounding in the same area as depth jumps, ie a super method.. if it isn't, it has to be creeping close to that spectrum though, single leg bounds are very intense.
I don't think it should be prescribed high volume + high box height in combination with lots of other work. Then I think it would actually be very detrimental & extremely risky.
On another note, i've done sessions with TONS of reactive work. Overdoing it to the max, all kinds of different varieties of things. I don't recall any of that being as intense as 4x10 depth jumps from 30". 40 total DJ's from 30" had my CNS destroyed and next-day ligaments/tendons feeling wrecked. Performing DJ's towards the second half (reps 5-10) of a set required some serious focus; it felt on the level of a max effort single in terms of how I would have to dial in. I havn't experienced that from lower volume protocols such as 3x3, 3x5 etc.
Finally.. My body is afraid of depth jumping until it's actually prepared. I can go do double leg bounds, kangaroo hops, attempt single leg bounds right now with my severe lack of prepardness.. However, if someone told me to go perform some DJ's from 30" i'd have some serious inhibition. I'd actually be afraid to do it. I could do a depth drop from 30" but I wouldn't even try a DJ from 30" right now (without prepping for several weeks). I find that interesting.
Interesting stuff. I guess my question more specifically is what do you think is unique to the depth jump that makes it more than reactive work, what specifically makes it a super method? Is there:
1) Something involved in stepping off the box? This seems unlikely. If it isn't that then why would the following not be a super method:
Jump up grab the rim with two hands (32 inch jump for me). Hang on rim. Release and upon landing jump back up and grab rim again. Would these rim grabs not be a super method? If not, then why not??
2) Something involved with the rest interval between each rep? Maybe? If not then why would repeated 30''+ jumps not be a super method? Ie jump vertical in place 30'' and repeat 10x times.
3) Something involved in the reversal of force in only the vertical direction? If not, then why wouldn't bounds or hurdle hops qualify as a super method provided the athlete goes 30'' in the air and comes down and rebounds.
Finally, I tried a few depth jumps. I jumped off a 34'' box and landed and touched a ceiling that is 10'1 I was able to get into the ceiling about 2 inches so it's about a 10'3 touch or a 31 inch jump for me. At the time I was wearing a weighted vest + weighted shorts (20+15) so my bodyweight went from 215 to 240 and my standing vertical touch was just barely 10'. Given that I am jumping higher off the box means I must be using some of the landing force in my jump. However, I timed the landing time and it was 0.44 seconds. Does the longer landing time disqualify it from being a depth jump? I took a video of the last two, let me know what you think (I realize if I embark on this it would be best without the additional weight, but I was already wearing it and wanted to get a video)...
http://www.youtube.com/watch?v=KbTVp0yAcu8
-
So I'm wondering... how much do depth jumps help your standing vertical in relation to your... depth jumps?
I mean say you have a 30" standing vert. You do DJ from a two foot box and get 32"
Let's say you do them for a few weeks and now your DJ from two foot boxes get you to a 35" jump.
Will your standing vert have increased by the same amount?
I like to do 5 max effort standing jumps before squatting. Should I switch to DJs?
-
So, DJ in my opinion (and experience) is a much more intense tool than pretty much all of the reactive work. Incorporating it as prep work or in lower volume should provide some benefit. I've seen studies claiming benefits in a variety of protocols, but not sure if some of those studies showed benefits simply from supplementing them into an existing program full of beneficial reactive work.
Also, He never mentions single leg bounding in the same area as depth jumps, ie a super method.. if it isn't, it has to be creeping close to that spectrum though, single leg bounds are very intense.
I don't think it should be prescribed high volume + high box height in combination with lots of other work. Then I think it would actually be very detrimental & extremely risky.
On another note, i've done sessions with TONS of reactive work. Overdoing it to the max, all kinds of different varieties of things. I don't recall any of that being as intense as 4x10 depth jumps from 30". 40 total DJ's from 30" had my CNS destroyed and next-day ligaments/tendons feeling wrecked. Performing DJ's towards the second half (reps 5-10) of a set required some serious focus; it felt on the level of a max effort single in terms of how I would have to dial in. I havn't experienced that from lower volume protocols such as 3x3, 3x5 etc.
Finally.. My body is afraid of depth jumping until it's actually prepared. I can go do double leg bounds, kangaroo hops, attempt single leg bounds right now with my severe lack of prepardness.. However, if someone told me to go perform some DJ's from 30" i'd have some serious inhibition. I'd actually be afraid to do it. I could do a depth drop from 30" but I wouldn't even try a DJ from 30" right now (without prepping for several weeks). I find that interesting.
Interesting stuff. I guess my question more specifically is what do you think is unique to the depth jump that makes it more than reactive work, what specifically makes it a super method?
well in regards to depth jumps, the ability to overload using the height of the falling body is what makes it unique. In the case of sprinting, some form of overspeed while maintaining mechanics (downhill sprinting or some kind of wind tunnel, who knows heh!) would qualify as a super method because you're using the falling body as an added stimulus. we can increase the height of the box/drop (depth jumps) or decrease the angle (down hill sprinting). I need to see if there are any studies on downhill sprinting, I remember doing searches before but I forget the results. Verk mentions it on several occasions but most of his actual data revolves around DJ's.
Is there:
1) Something involved in stepping off the box?
nah
This seems unlikely. If it isn't that then why would the following not be a super method:
Jump up grab the rim with two hands (32 inch jump for me). Hang on rim. Release and upon landing jump back up and grab rim again. Would these rim grabs not be a super method? If not, then why not??
right, that's basically a DJ. the only difference is you can't increase the height of the drop precisely, resting seems more difficult, controling angles isn't as easy (you drop right down), and gathering yourself would probably be more effective if you drop off of a box.. but it's the same concept IMHO.
2) Something involved with the rest interval between each rep? Maybe? If not then why would repeated 30''+ jumps not be a super method? Ie jump vertical in place 30'' and repeat 10x times.
well it sounds like it would be but, if you can repeatedly jump 10x and hit 30", then a 30" box is probably too small to be effective overload as a super method. In that case you might need a 36" box etc. The fact that someone jump 10x in a row with no rest in between (rebounding vertical jumps) and hit 30" means that it is a submax effort, a "10RM" in a sense. So that athlete would need a higher box to tap into that "protected motor potential".
I mean I guess you can label DJ's from 12" "shock", but, it's not true shock in the sense that it isn't a powerful enough overload stimulus. So 30" is the low end of Verk's recommendation, 42" on the high end. Box height is determined by the performance/strength stats of the athlete.
3) Something involved in the reversal of force in only the vertical direction? If not, then why wouldn't bounds or hurdle hops qualify as a super method provided the athlete goes 30'' in the air and comes down and rebounds.
Same reason as above. If an athlete can get their COG 30" above ground on DL/SL bounds etc, they already posses the "special strength" to produce and absorb/redirect that force voluntarily. So in order to tap into that extra motor potential, they would need to practice DJ's from higher boxes.
Even with single leg bounds, if you're able to keep bounding and reach some y-height (30" for example), it's a voluntary effort and according to Verk, falls within your "special strength" motor potential, not the "defended motor potential".
Finally, I tried a few depth jumps. I jumped off a 34'' box and landed and touched a ceiling that is 10'1 I was able to get into the ceiling about 2 inches so it's about a 10'3 touch or a 31 inch jump for me. At the time I was wearing a weighted vest + weighted shorts (20+15) so my bodyweight went from 215 to 240 and my standing vertical touch was just barely 10'. Given that I am jumping higher off the box means I must be using some of the landing force in my jump. However, I timed the landing time and it was 0.44 seconds. Does the longer landing time disqualify it from being a depth jump? I took a video of the last two, let me know what you think (I realize if I embark on this it would be best without the additional weight, but I was already wearing it and wanted to get a video)...
http://www.youtube.com/watch?v=KbTVp0yAcu8
looks good. form-wise, it could perhaps use a bit more of a pronounced step off (one leg, arms come together, then other leg as you gather in the air then drive the arms back), and actively dorsiflexing the ankles as you step off, but that's debatable anyway.
I don't think that GCT disqualifies it at all.. you would have to compare it to unweighted jumps and making sure you are rehearsing the correct cues:
"land with a spring and then fly as high as possible" -- SSTM p100
that cue determines the correct execution of the exercise, according to Verk. So, if you practiced DJ's semi-frequently (low volume) and rehearsed the correct cues (and performed them without extra weight), then whatever your GCT is I would imagine it is acceptable (within reason, 1+ second is unacceptable for example). As you improve MaxS, ExS, ReaS, that GCT should either stay the same while producing more force, or perhaps decrease while producing as much or more force.
i'm going to type out a few sections from SSTM on Shock & DJ's.. it will be worth it, some nice information in there and he says it alot better than I can say it :D
give me a bit!
pc man!
-
So I'm wondering... how much do depth jumps help your standing vertical in relation to your... depth jumps?
I mean say you have a 30" standing vert. You do DJ from a two foot box and get 32"
Let's say you do them for a few weeks and now your DJ from two foot boxes get you to a 35" jump.
Will your standing vert have increased by the same amount?
maybe not by the same amount, but yes it should increase. Your DJ improving by 3" implies improvements in maximum strength, explosive strength, and reactive strength. So by that alone, and the high amount of dynamic correspondence towards a counter movement jump, you should definitely see improvements in CMJ.
The drop height can add the extra load to your body which you're utilizing via the strength shortening cycle and such.. so without the box, you would now have to generate that force with a much less powerful stimulus (the counter movement).. but, the DJ should be improving several strength qualities that you will be able to voluntarily express during your CMJ.
I like to do 5 max effort standing jumps before squatting. Should I switch to DJs?
i'd still warmup with some CMJ's before DJ's.. and you'd still need to spend a few weeks prepping on lower boxes, don't jump right into a 30" box. You should easily be able to handle an 18" box for a few weeks, then try a 24" box.. re-evaluate after a few weeks using the 24" box.
use your CMJ prior to the DJ to set a goal for you to beat when you're DJ'n. A vertical goal (touch height etc) is important.
pc man
-
So I'm wondering... how much do depth jumps help your standing vertical in relation to your... depth jumps?
I mean say you have a 30" standing vert. You do DJ from a two foot box and get 32"
Let's say you do them for a few weeks and now your DJ from two foot boxes get you to a 35" jump.
Will your standing vert have increased by the same amount?
maybe not by the same amount, but yes it should increase. Your DJ improving by 3" implies improvements in maximum strength, explosive strength, and reactive strength. So by that alone, and the high amount of dynamic correspondence towards a counter movement jump, you should definitely see improvements in CMJ.
The drop height can add the extra load to your body which you're utilizing via the strength shortening cycle and such.. so without the box, you would now have to generate that force with a much less powerful stimulus (the counter movement).. but, the DJ should be improving several strength qualities that you will be able to voluntarily express during your CMJ.
I'm going to be annoying for a second and mentally masturbate
How much more effective are DJ's than CMJ's at improving the CMJ?
advantages of DJ: increased load leading to slight max strength improvements, rate coding improvements, reactive strength improvement (can we define reactive btw)
advantages of CMJ: specificity to the CMJ... but I'm sure it can also improve reactive strength to some extent and rate coding and all that.
-
Oh another thing
I think a long time ago an article was posted about why exactly a plyometric movement leads to more strength output. and it said it's mainly caused by the tendons stretching so that the muscle can contract isometrically for a moment rather than concentrically the whole time. the advantage this gives is that muscles can contract with more force eccentrically, then isometrically, than concentrically.
anyone know what I'm talking about? its very interesting and makes a lot of sense
-
Is explosive strength training that is not reactive-based necessary at all in the face of reactive training?!
I mean, what do paused jump squats do that depth jumps can't?
-
I will also add another question to Dreyth's multiple great questions (that I also am wondering the answers to)
Adarq,
Would Depth Jumps be effective improving CMJ and DLRVJ for someone who is VERY hip dominant? Little knee bend, lots of forward bending at the hips/waist, very glute dominant jumper. A DJ is very quad dominant. I'm assuming DJ's in this sense will not have much of a carryover since there isn't much of that quad strength/dominance for the DJ's to take advantage of/peak out right?
Maybe for these guys, backward DJ's would be better?
edit:
Also, So if someone increased overall lower body strength significantly using something not THAT intensive like 3 x 8 intensity of squats, he can obviously can peak out his maximal strength gains without any hypertrophy by recruiting more already present motor units through traditional high intensity low rep squats (something like 4 x 3 @ 90%+).
Can this also be done without low rep heavy lifting and instead using intense depth jumps (although may not be as efficient/fast as low rep lifting)???
-
From SSTM for Coaches! Verk's last book (epic book). Written verbatim, some grammatical weirdness is due to the authors.
(p87-88)
2.4.2 Shock Regime
The Shock Regime is characterized by a sharp, sudden force effort of muscles stretched by a former short, powerful impact against an external opposition. It is used to develop Explosive Strength, Reactive Ability, and Maximal Strength. This regime is characterized by a great training effect on the motor and neuromuscular system and on the central mechanism that regulates muscle contractile function. At the end of the 1960s, after having verified its efficacy in sport practice, it was adopted as special training regime for high-level athletes only.
The Shock Regime was thoroughly investigated in the Y.Verkhoshansky's research in 1960s. The idea behind this method is in the use of the body (or training device) kinetic energy, accumulated in its free fall, to stimulate neuromuscular tension. The neuromuscular tension is provided at the contact after dropping from a specific measured height. The body landing causes a relatively short phase of amortization that causes a sharp 'shock' stretching of the muscles. That brings to two interrelated reactions of the neuro-muscular system:
- increasing the motor neurons stimulation intensity;
- creating an elastic potential of muscle tension.
That assures an increase in speed of the subsequent muscle contraction during the fast switching from pliometric (yielding) to miometric (overcoming) regime.
<skipped info regarding the use of the term pliometric, plyometric, etc>
According to Y. Verkhoshansky, also the use of the term 'pliometric', to define the Shock Method, is not correct; the principal training factor involved in this method is not simply the former muscles stretching in yielding regime, but rather the fast switching from sharp shock stretching to vigorous contraction. The simplest form of performing the exercise in the Shock Regime is the Depth Jump; a vertical double leg jump after a drop down from a carefully measured height.
this part is related to devices similar to the Plyo Swing, but still good info (not as much this next paragraph, but the one after):
A particular form of Shock Regime exercises for training different muscle groups is showing in Fig. 2.12 (picture weights on some pulley system falling on you and then you push them etc, heh). At the start, the weight is freely lowered, approximately 2/3 of the total range of movement, it is followed by a sharp downwards-upwards movement. The consequent fast twitching of the muscles, from yielding to overcoming regime, produce a vigorous acceleration of the load. In order to avoid injury it is necessary to provide limiting devices to block the movement of weight from going further than necessary.
In the preparation of the exercise execution, consider the following:
- The starting position is selected after taking into consideration the position of the body at which the maximum working effort is expressed in the competition exercises.
- The initial pathway should be minimal but sufficient to create the shock tension in the muscles.
- The size of the shock effect is determined by the overload weight and by the height from which it falls. The optimal combination of these two factors has to be empirically determined. However, preference should always be given to greater height rather than greater weight.
- The exercises in the Shock Regime should be executed only after an adequated warm up.
- The dosage for shock exercises depends on the 'quality' of execution and should not exceed 4 sets of 10 repetitions. When the athlete executes for the first time this exercise, than the dosage should not exceed 2-3 sets of 5-8 repetitions.
It must be eemphasized that the Shock Method is not to be taken lightly. Recently, mainly in the USA, variants of depth jumps have been presented by many authors. They often suggest exceeding the optimum dosage of Depth Jumps and the recommended height of the drop-down, as well as their use for low level athlete.
The Shock Method has an extraordinarily strong training effect on the nervous-muscular system; considerably stronger than any other natural method of stimulation of the contractile activity of the muscles. It is, therefore, inadmissible to exceed the optimum dosage and duration of Depth Jumps use in the training process, as well as the recommended height of the drop-down. The Depth Jumps have a strong training effect on the ligaments and joints and, consequently, it is necessary to:
- prepare the athlete in advanced, performing jumping and resistance exercises.
- study the technique of executing exercises in the Shock Regime, especially when the muscles are working in the push-off (take-off) after the drop down. This is not as simple as it may seem so initially;
- never use the Shock Regime when tired (when muscles are sore), when undergoing the treatment for injuries or in combinations of resistance exercises in different regimes.
The Shock Method is for high-level athletes. It should never be applied in the training of low-level athletes. for the latter, there are different and sufficiently effective SST (Special Strength Training) means.
It is incorrect to overestimate the possibilities of the Shock Method. It is only one of many ways of intensifying the work of the neuro-muscular system. Shock Method used alone, cannot replace all the other methods, it should be applied together with other means and methods and have a definite place in the SST system.
(p99-100)
3.4 Depth Jump
Depth Jump or Shock Method Jump is a very efficacious mean for developing Explosive Strength and Reactive Ability. At the present time this is a training means that is popular and its use is widespread all over the world. Although it has acquired many take-off execution variants, its main form is the vertical two leg take-off.
Despite its apparent simplicity, the eecution technique of Depth Jump is quite complex and in many cases, it is performed incorrectly. First of all, this can lead to an excessive load to the knee and tibio-tarsic joint, creating a trauma risk. Secondly, it can reduce the training effect of this exercise on the organism.
This is the reason why, at the beginning of Depth Jump use, it's worth illustrating the correct execution of this exercise. After, the athlete must not think about it: correct execution of this exercise will be obtained to the athlete's correct understanding of the motor trend of this exercise.
Drop Phase - The Drop Jump (stepping off an elevated surface) is an important particular of the tecnique that greatly influences the correct execution of the whole exercise.
The athlete must not step off with both the legs, but rather take a step forward with one leg and, at the beginning of the fall, bring the other leg forward, reuniting the two legs. The athlete must not bend the legs prior to stepping off the elevated surface (legs must be straight) and must not jump, but drop forward - the fall trajectory must be perpendicular to the ground.
Landing Phase - The athlete must land on both legs, on the ball of the feet, and then quickly lean back on the heels. Landing should be flexible with a substantial passage to cushioning and then to take off.
Cushing and Take-Off Phase - The passage from cushioning to take-off is very quick. Before the landing both the arms are put backward and at the moment of the take-off they should move upwards with a quick and powerful thrust. The cushioning and take-off phases should be executed as a single action with a powerful concentrated effort.
Flight after the take-off phase - To reach the highest point of flight after the take-off, the athlete should fix a point of reference (for example, a small flag) to reach for, trying to touch it with one or both hands. After the flying, the athlete should gently land on the balls of both feet with a flexible cushioning.
"Land with a spring and then fly as high as possible" - this should be the motor trend that the athlete should acquire for facilitating the correct technical execution of the exercise. The athlete's understanding of the Depth Jump motor trend determines the correct execution of all its phases and its training effect on the neuro-muscular system. The visual point of reference (small flag) is a very important element; it emphasizes the final goal of this exercise.
The Depth Jump has a very strong effect on the central nervous system and on the muscular-skeletal system. This is why it should be used, above all, in the training of well-prepared athletes and only after a preparation period that includes a substantial volume of bounding exercises and jumps with an overload.
The athlete should begin with low drop height, from 0.4 to 0.5m, and gradually work up to reaching the optimal height of 0.75m. He must not use other jump exercises after the depth jump, especially when tired or suffering muscle pain or traumas that have yet to heal.
(p102)
Improving Reactive Ability
1) Depth Jumps:
- For high level athletes the optimal height of a depth jump is 0.75m
- Athletes of high preparation- dosage in a training session should not exceed 4 series with 10 takeoffs.
- Athletes of lesser preparation - 2-3 series with 6-8 repetitions, with 60cm height.
- The 4-5 minute rest periods between series consists of jogging and relaxation and flexibility exercises.
- During the preparation period, the takeoff exercises after the depth jump should be executed in a fixed quantity, 2 times (at most 3 times), and only after the preparation of preliminary strength (with overload) and the preparation of jumps and bounds.
- During the competition period they represent an efficacious means to maintain the achieved level of special physical preparation. In this period one should include them in the training once a week and then reduce their training frequency to once every 7-8 days before competitions.
so that's from his book SSTM for Coaches.
Also, there's more info in this article on his site: http://www.verkhoshansky.com/LinkClick.aspx?fileticket=bBhPjzgn%2B0A%3D&tabid=92&mid=426
-
Damn i really want to add some DJ's into my training. Just like 5x1 or something, but all max effort. Low box. Im in a strength building phase right now. 5x1 will do a good job of potentiating my squats and keeping some jumping efficiency.
But heres something thats been bugging me. And i seriously believe it needs to be addressed. I havent overanalyzed in a long time, but bare with me: Are DJ's worth your training time if youre naturally decently reactive?
I just feel like is more economical training wise for me to increase my squat:bw ratio rather than focus on plyos EVER. How long do your plyo gains stick around??? This is very important. When i lift for strength, if i take a few weeks off i lose some strength right away. It takes a few weeks to get it back after that. But most of the gains REALLY stick around. I mean if i go from a 200lb to 300lb squat and then take a few weeks off, i may hover at 270lbs so im still benefitting from having increased my squat even though i havent squatted in a while. Another important fact is that max strength has a very high ceiling. But not only that, increasing max strength increases RoFD as well!!!
Three iportant things to take away: after not squatting for a while you still benefit from having squatted for a long time preceding the hiatus. The high ceiling on max strength. Increasing max strength increases RoFD. These three make it "worth it" (highly economical) to increase relative strength.
Movement efficiency has a very low ceiling. As an analogy, say i play a lot of bball from January through March. Say i dont play basketball from March through July so my vert suffers. But say i continue to make relative strength gains the entire year. When i start playing ball again in August, my vert starts going up again and by October Its is higher than what it was in January due to the relative strength gains i made since January.
So Would it ever be really necessary to waste time keeping that movement efficiency from Jan through Oct really? I mean, do basketball players stay conditioned in the off season? Not really. Its quickly lost and quickly gained, so why stay conditioned in the off season when you can just condition yourself for a couple weeks before the next season starts?! Like conditioning, feel like the ceiling on movement efficiency is hit pretty quickly so theres no real need to keep it up in the long term. Just get it back when you need it.
But what about DJ performance? If you are regularly doing 5x5 from a high box, then youre kicking ass at them because thats tough. But lets say you take a few weeks off from doing that. How long until you get back at the same jump heights on that highbox?? If it takes very long to get it back, then that sucks and its not so worth busting your ass with them (if youre naturally decently reactive). If you can get it back quickly however, then thats similar to the movement efficiency analogy i gave and it may mean DJ's have a low ceiling. So again it may not be sp worth it.
So where does that leave us? Well it sucks if DJ performance takes long to get back that sucks. But if it can be regained quickly that means it may have a low ceiling... Then the most important question is.... Much like increasing your max strength... If you increase your reactive ability from 20 units to 100 units, and then dont train it for a long time. Does it drop back to 20 units, or does it hover around 70 units so you are still benefitting from having done DJ's? Or is it more like movement efficiency, where you can go from 100 units and down to 20 units, but very quickly back up to 100 units ahen needed. That really is the golden question.
This brings up SO many questions in terms of programming. I have a hunch that at least for athletes like me (naturally decently reactive) depth jumps should pretty much be saved for peaking phases. Its not worth making them a big part of my training when it means my strength will stall during those phases and the DJ gains have a low ceiling, are quickly lost, and do not be efit me anymore if i were to have stopped doing them for a few weeks. I mean how much is my squat going to increase when im DJing 4x10 twice a week? Fuck that id rather just focus on building max strength.
Then when i have to focus on strength again... Ill have to cut back on the DJ a lot but then ill probably lose DJ performance, you know? So its like... I made those temporary gains, but now that i want to increase my squat:bw ratio and make aome permanent vert gains, DJ take a back seat.
With my limited knowledge i conclude (but really shouldnt; my assumption is based on the idea that depth jump effienciy is quickly lost and doesnt benefit you for long when untrained, much like movement efficiency) that for people naturally decently reactive, and for long term gains (so ignore peaking phases), DJ's should be limited to being an excellent potentiation exercise before heavy squats. And they will do a great job of improving and keeping jumping efficiency damn high. Anyway, lets not forget, increasing your max squat increases your RoFD by a significant amount -- especially if every rep is performed at 100% effort. Remember, its not the bar speed, its the intended speed that counts. This makes an even greater case to train moreso for relative strength than to focus efforts on DJ's -- no need to have strength take a back seat to increase RoFD when heavy squatting does that too (admittedly to a lesser extent, but dont forget DJ gains are lost).
At the end of the day, i wont play basketball for months right. So my very will drop from 36" to 30". But then ill make great relative strength gains. And my vert will be at 32". Then when i play a ton of ball again, my vert will shoot to 38". Over the years my training has gotten simpler: figure out what micro and macro cycle set ups help improve my squat:be ratio the most... And then go out and jump. If i were to think long term, DJ's should only have their place when (1) my squat:be is so difficult to improve past a certain point that its more economical to focus on reactive strength, or (2) increasing squat:bw ratio fails to yield an increase in vertical thats worth the effort, its time to focus on DJ's since they will be more economical at that point.
In other words, by the time it makes sense for me to focus on DJ's from a long term, holostic perspective of my training career (ignore potentiation for squats), i will be using them to reach only the pinnacle of my jumping ability.
-
If nobody feels like reading all that, i basically argue that for people who are decently naturally reactive theres no need to focus on DJ's unless you are nearing the end of your training career defined as not seeing returns on increasing your squat:bw ratio that are worth the effort. Only then is DJ centered training economical. The fact that increasing max strength increases RoFD as well, also plays a big role in this.
-
I just feel like is more economical training wise for me to increase my squat:bw ratio rather than focus on plyos EVER. How long do your plyo gains stick around??? This is very important. When i lift for strength, if i take a few weeks off i lose some strength right away. It takes a few weeks to get it back after that. But most of the gains REALLY stick around.
The gains are sticking around because you haven't lost strength. You have lost movement efficiency in the squat. That's why it might take you 3 months to go from 250 to 275 and another three to go from 275 to 300, but after taking time off and going back down to 270 you can get back to 300 in a matter of weeks. One thing you will notice is that the "increased strength" from going back to 300 from 270 won't have any carryover. That's because for most people squats have very little direct carryover to jumping (far less than bounding, depth jumps, sprints, etc). The increase in the jump from squats is the side effect of squats - larger lower body muscles, stronger core muscular, etc. But that's the problem with your claim that maximal strength has a higher ceiling - as we get stronger we make more and more squat gains because of squat movement efficiency... These won't carry over.
If nobody feels like reading all that, i basically argue that for people who are decently naturally reactive theres no need to focus on DJ's unless you are nearing the end of your training career defined as not seeing returns on increasing your squat:bw ratio that are worth the effort. Only then is DJ centered training economical. The fact that increasing max strength increases RoFD as well, also plays a big role in this.
What's interesting is that you present yourself as a naturally reactive athlete (and I'm not here to tell you that you are not) but keep stating the carryover of maximal squat strength to your jumping ability. Truly reactive athletes don't see returns on increasing their squat:bw ratio from jump. They essentially begin at what you define as the end of their career. Depending on their build and level of starting strength some will see gains from squat:bw ratios if they are very weak - but these are fleeting. My max squat was a shaky above parallel 185lbs when I was in highschool - I was 5'11 170 and could dunk off 1 foot and rim out my attempts off two feet and could run 11.2 in the 100m. My jumping ability (svj,dlrvj,slrvj was about 28'', 33', 35'') . After getting in the weight room and getting to the point where I could nail 5x5x225lbs ATG @ 5'11 183 I was able to run 10.6 and my jumping ability was ~ 30'',38'',36'. Interestingly I tried deadlifting for the first time then and could do 405 on my first try... Anyway, years later I built my squat to 500lbs @ 205lbs and achieved jumps of ~ 34'', 38, 34''. My gains from squat:bw ratio essentially were maxed out by the time I could handle 225lbs...
Sorry for the long digression but I think this reminds me of one very important coaching tip: Sometimes we have to train to our strength. You might have good reactive and maximal strength expression in your jump. Which is the point your making - essentially that you should focus on your weakness because it will give you the best bang for your buck... This might be true for you. But for those on the extremes it's important to recognize that while it seems counterintuitive focusing on your weak link is often the worst thing you can do. We see this all the time in sprints. You have an aspiring 400m runner with runner who has amazing top speed and mediocre speed endurance ( say 100/200/400 10.4/20.8/46.5 ) - the runner dies at the end of the race. A well meaning coach immediately looks at the athlete and decides that the athlete has "enough" speed and needs to focus on speed endurance. After getting far more speed endurance the athlete comes back and now has the ability to run 46.0 (but has splits of 10.6/21.3/46.0). It's terrible coaching and it happens all the time. Initially the athletes 400 time was "bad" relative to his 200m (a 20.8 200m predicts a 45.3) not it's "good" because a a 21.3 predict a 46.8. I've gone through this cycle with coaches and it's really frustrating. The coach should have done a little endurance work throughout the year but kept emphasis on speed - the athlete would have been better served getting their 100m and 200m down to 10.2 and 20.5 then neglecting their natural ability to gain speed endurance...
The same is true for jumps. The really reactive guy - he needs to focus on reactive work. Sure maximal strength training should probably take place but it should not be emphasized. The really reactive guy is the one who needs the depth jumps! His bang for the buck for reactive training is far greater than the other guy, in other words he is the best athlete he can be when he is squeezing out 95% of his reactive potential and 70% of his maximal strength potential. Same thing with the other way around... get the non-reactive person as strong as possible. Reactive work is his background training... Sometimes we have to train our strength and just be conscious of our weakness.
-
The gains are sticking around because you haven't lost strength. You have lost movement efficiency in the squat. That's why it might take you 3 months to go from 250 to 275 and another three to go from 275 to 300, but after taking time off and going back down to 270 you can get back to 300 in a matter of weeks. One thing you will notice is that the "increased strength" from going back to 300 from 270 won't have any carryover. That's because for most people squats have very little direct carryover to jumping (far less than bounding, depth jumps, sprints, etc). The increase in the jump from squats is the side effect of squats - larger lower body muscles, stronger core muscular, etc. But that's the problem with your claim that maximal strength has a higher ceiling - as we get stronger we make more and more squat gains because of squat movement efficiency... These won't carry over.
I agree with everything you are saying and already knew it, except for the following:
- I have always had a direct carryover to my jumps from increased squat strength relative to bodyweight, even when I was a 1 foot jumper. Admittedly the carryover will have diminishing returns, and part of the reason is because after a certain point i'm just gaining a much higher proportion of squat specificity versus muscle strength thats used in jumping. but the single most important thing I have ever done is taken my squat from 1x bw to 2x bw.
- I think you're undermining the "high ceiling" of strength gains. Compare it to the gains from DJ's and stuff. Taking your squat from 1x bw to 2x bw makes a hell of a difference. Max strength is a more trainable quality than reactive strength, even ignoring that much of the gains may be from specificity in the squat. This is what I mean by it has a "high ceiling."
What's interesting is that you present yourself as a naturally reactive athlete (and I'm not here to tell you that you are not) but keep stating the carryover of maximal squat strength to your jumping ability. Truly reactive athletes don't see returns on increasing their squat:bw ratio from jump. They essentially begin at what you define as the end of their career. Depending on their build and level of starting strength some will see gains from squat:bw ratios if they are very weak - but these are fleeting. My max squat was a shaky above parallel 185lbs when I was in highschool - I was 5'11 170 and could dunk off 1 foot and rim out my attempts off two feet and could run 11.2 in the 100m. My jumping ability (svj,dlrvj,slrvj was about 28'', 33', 35'') . After getting in the weight room and getting to the point where I could nail 5x5x225lbs ATG @ 5'11 183 I was able to run 10.6 and my jumping ability was ~ 30'',38'',36'. Interestingly I tried deadlifting for the first time then and could do 405 on my first try... Anyway, years later I built my squat to 500lbs @ 205lbs and achieved jumps of ~ 34'', 38, 34''. My gains from squat:bw ratio essentially were maxed out by the time I could handle 225lbs...
Sorry for the long digression but I think this reminds me of one very important coaching tip: Sometimes we have to train to our strength. You might have good reactive and maximal strength expression in your jump. Which is the point your making - essentially that you should focus on your weakness because it will give you the best bang for your buck... This might be true for you. But for those on the extremes it's important to recognize that while it seems counterintuitive focusing on your weak link is often the worst thing you can do. We see this all the time in sprints. You have an aspiring 400m runner with runner who has amazing top speed and mediocre speed endurance ( say 100/200/400 10.4/20.8/46.5 ) - the runner dies at the end of the race. A well meaning coach immediately looks at the athlete and decides that the athlete has "enough" speed and needs to focus on speed endurance. After getting far more speed endurance the athlete comes back and now has the ability to run 46.0 (but has splits of 10.6/21.3/46.0). It's terrible coaching and it happens all the time. Initially the athletes 400 time was "bad" relative to his 200m (a 20.8 200m predicts a 45.3) not it's "good" because a a 21.3 predict a 46.8. I've gone through this cycle with coaches and it's really frustrating. The coach should have done a little endurance work throughout the year but kept emphasis on speed - the athlete would have been better served getting their 100m and 200m down to 10.2 and 20.5 then neglecting their natural ability to gain speed endurance...
The same is true for jumps. The really reactive guy - he needs to focus on reactive work. Sure maximal strength training should probably take place but it should not be emphasized. The really reactive guy is the one who needs the depth jumps! His bang for the buck for reactive training is far greater than the other guy, in other words he is the best athlete he can be when he is squeezing out 95% of his reactive potential and 70% of his maximal strength potential. Same thing with the other way around... get the non-reactive person as strong as possible. Reactive work is his background training... Sometimes we have to train our strength and just be conscious of our weakness.
This is a lot to take in at once, but one important thing i took away is that in the case of training our VJ, a very reactive person is better off still focusing a bunch on training reactivity versus max strength? I probably understood it wrong.
Anyway my main gripe with DJ training is... we know that the increased strength from the squats sticks around long after you stop squatting. But does the RoFD from DJ's stick around long after you stop DJing?! Because if it doesn't, then why would I ever program it into my training for purposes other than peaking or potentiation? Not to mention it can get in the way of maximal strength training... PLUS throw in the fact that maximal strength training helps increase RoFD as well (not reactive strength though).
Thanks for taking the time to read and respond. I like your sprinting example a lot.
-
merrick/dreyth, i'm going to reply soon. was going today but didn't get around to it. just letting you know.
pc!
-
well in regards to depth jumps, the ability to overload using the height of the falling body is what makes it unique. In the case of sprinting, some form of overspeed while maintaining mechanics (downhill sprinting or some kind of wind tunnel, who knows heh!) would qualify as a super method because you're using the falling body as an added stimulus. we can increase the height of the box/drop (depth jumps) or decrease the angle (down hill sprinting). I need to see if there are any studies on downhill sprinting, I remember doing searches before but I forget the results. Verk mentions it on several occasions but most of his actual data revolves around DJ's.
I read over this before but forgot to mention my opinion of downhill sprints. IMO they are not worth the danger for many reasons - one obvious reason it's hard to find a safe semi-soft level surface that is also a hill... A wind-tunnel would be great but what most coaches do today is just a pulling belt. We used to train where we would run 40m with a stretched belt that attached to the torso - at 40m the belt would clip off but we would be left with the footspeed we created with our own power and the belt tension...
In sprinting we call this overspeed training. It's a similar idea to DJ in that coaches claim that our inability to run faster is due partially to muscle/tendon complex incapable of creating enough force and but also because of some type of neural inhibition that we can reduce by running faster than we ever have through some added stimulus. It's interesting that he includes downhill running and depth jumps as similar method because when I compare the two they have a completely different mechanism for the following reasons:
1) Vertical jumping is a battle against gravity. The depth jump requires the athlete to overcome this force not from a static position but to rebound at constant acceleration downward and produce upward acceleration. The 100m sprint is actually a battle against air resistance. Usain Bolt spends 85% of his energy battling air resistance. After battling inertia to start the race the sprinters main enemy is a horizontal force - not a vertical force.
2) Running downhill falsely increases stride length which causes the athlete to increase stride frequency to keep up. It's been shown over and over that stride frequency is never a limiting problem for sprinters. Additionally, a foot falling from a height will have a different footstrike than on a flat surface.
3) Depth Jumping does not cause the body to accelerate faster (jump higher) than their current limit while downhill sprinter puts the runner at speeds they haven't experienced. What would be interesting is some type of assisted jump that allowed the athlete to jump higher, for example a short depth jump with bands that pull down on the fall, then release while bands that pull upward are activated... This will cause the athlete to experience a faster eccentric and concentric.
Speaking of for #2. It's unfortunate how uneducated some trainers are. I was training at a gym for athletes where some people were using the Vertimax (I don't see the utility in this tbh) and one trainer said about depth jumps (you can either go to a higher box or just hold some dumbells in your hand to fall faster)... Seriously? However, it did remind me of a training tool I saw the athletes using at Baylor. Wonder what your opinions are. The idea behind the contraption was sort of the opposite of the trainers mistake, as follows:
1) We can drop from a box and rebound up. Holding weights is not as effective as a higher box because we won't fall faster we will just have more weight to reverse. Dropping from a 0.5 meter box vs a 1 meter box will mean a difference of hitting the ground at roughly 3 m/s vs 4.5 m/s. This speed at GCT that we have to absorb and reverse is what makes DJ effective. However, no matter how high the box we will always accelerate at 9.8 m/s^2... What if the athlete accelerates supra maximally and has to reverse that force. So basically a DJ where the athlete steps off and has band tension that pulls him off, at GCT the bands are released from his torso and he jumps up. This coach swore by it as the most effective tool. I don't know if it was necessary but it was clever...
-
I agree with everything you are saying and already knew it, except for the following:
- I have always had a direct carryover to my jumps from increased squat strength relative to bodyweight, even when I was a 1 foot jumper. ... the single most important thing I have ever done is taken my squat from 1x bw to 2x bw.
It's great that you replied in detail because I think that this claim actually shows how different jumps are. You can correct me if I am wrong but I feel like your line of thinking goes:
1) I was a one footed jumped which is clearly a far more reactive technique than DLRVJ.
2) Therefore I am really reactive.
3) My squat made my legs stronger and I jumped higher.
4) Therefore, increasing squat == increasing jump across the board for reactive or strength oriented jumpers.
***************************************************************************************************
I think that you should carefully consider each of these points and how they could be false:
1) We often forget that while the one footed jump has a far greater speed component than the SVJ - there is still a hell of a lot of diversity when it comes to one footed jumps. Their was a paper that showed how drastically different Carl Lewis and Mike Powells take off is - one begins with a lowering of COM 2 strides away to prepare for the jump while the other essentially springs out of the penultimate and accelerates into a final step and jump. If you look a high jump analysis there are a great many ways to jump. Their are strength 1-footed jumpers, reactive 1-footed jumpers, hip-tendon dominant 1 footed jumpers, achilles jumpers, fascia speed jumpers, etc.
2) You are capable of carrying horizontal speed into a jump and making use of it but that doesn't mean you are not a strength 1-footed jumper. I can barely grab the rim from a SVJ. Give me a single drop step and I can dunk the ball easily. However it's still a strength jump.
3) Maybe. At what level of an athlete were you before squatting? Maybe you are quite reactive but were really weak - ie had zero core strength, no low back strength and couldn't express your reactivity until you got some general strength. Maybe it's not your squat going from bw to 2bw but just the general strength that allowed you to maintain stiffness in the jump - general strength that could have been obtained through sprinting or other training that wouldn't have increased squat.
4) For the above 3 points you can see why this is not necessarily true. You could also just consider the high-jump over head world record holder, Stefan Holm. He is 5'10 and jumped 7'10. It's hard to convert that into a vertical jump but getting your COM 7'10 from 5'10 even with perfect flop technique suggests that he easily has a 50'' SLVJ. Despite this 50+ SLRVJ his standing vertical jump is only 23''. He mostly uses an empty barbell in training. He hasn't squatted near 2x bw. Do you honestly think that if he got his squat to 2xbw his jump would get better? He is already the world record holder in height above head and 2inches from the world record set by a 6'6'' guy...
Consider the diversity of both people and jumping... Squats were specific to your body to increase your jumping but that just can't be generalized easily...
-
Lol, T0ddday, you just answered my question on here that I was asking on the High Jump Thread... 50" SLRVJ... crazy
-
Good points Todday. I hope DJ's can increase my vert more than i think, and i hope its more permanent than i think too!