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Peer Reviewed Studies Discussion / MISC Animal Studies
« on: June 04, 2009, 11:11:23 pm »
All conclusions of studies will be listed in this original post (TABLE OF SUMMARIES) for quick reference.

Post anything relevant to studies done on animals / rodents etc. I'm not a big fan of animal testing, thought it does provide valuable information. There are some crazy studies that exist out there.

1. Intracranial self-stimulation motivates weight-lifting exercise in rats

At the end of the training period, the rats were lifting over 550% of the starting weight. Gastrocnemius size and mean fiber diameter were increased in the weight-lifting animals. This model combines exercise with positive incentive and has the advantages of being relatively easy to implement and not producing any apparent physical or mental trauma in the animal.

2. Mirror neurons and the simulation theory of mind-reading

A new class of visuomotor neuron has been recently discovered in the monkey's premotor cortex: mirror neurons. These neurons respond both when a particular action is performed by the recorded monkey and when the same action, performed by another individual, is observed.

3. Measurements of muscle stiffness and the mechanism of elastic storage of energy in hopping kangaroos.

3. When the muscle was developing close to its maximum isometric tension, up to eight times as much movement occurred in the tendon as in the muscle fibres. This is made possible by the wallaby having a long and compliant tendon.

4. Beneficial Effects of Exercise on Growth of Rats During Intermittent Fasting

When the fasted-EOD rats were also exercised, they gained 29% more weight, consumed 11% more feed and had carcasses that contained 29% more lean mass and 18% less fat than the fasted-EOD rats. The data suggest that exercise may be beneficial where feed restriction is episodic, allowing some capacity for catch-up growth.

5. Adaptation of Equine Locomotor Muscle Fiber Types to Endurance and Intensive High Speed Training

Endurance training results in increased mitochondrial density, capillary supply, changes in key metabolic enzymes, and increased maximal oxygen uptake and promotes a transition from type II to type I muscle fiber. In horses, prolonged aerobic exercise training has been shown to induce a further decline in the percentage of type IIx MyHC isoform expression and an increase of type I and IIa MyHC isoform expression. Short-duration, high-intensity exercise training stimulates type IIA and hybrid (IIA/IIX) fibers. Therefore, intensive high-speed trotting facilitates muscle fiber hypertrophy and increases the oxidative capacity of type IIX fibers.

6. 2003: Functional trade-offs in the limb muscles of dogs selected for running vs. fighting

The physical demands of rapid and economical running differ from those of physical fighting such that functional trade-offs may prevent simultaneous evolution of optimal performance in both behaviours. Here we test three hypotheses of functional trade-off by measuring determinants of limb musculoskeletal function in two breeds of domestic dogs that have undergone intense artificial selection for running (Greyhound) or fighting performance (Pit Bull). We found that Greyhounds differ from Pit Bulls in having relatively less muscle mass distally in their limbs, weaker muscles in their forelimbs than their hindlimbs, and a much greater capacity for elastic storage in the in-series tendons of the extensor muscles of their ankle joints. These observations are consistent with the hypothesis that specialization for rapid or economical running can limit fighting performance and vice versa. We suggest that functional trade-offs that prevent simultaneous evolution of optimal performance in both locomotor and fighting abilities are widespread taxonomically.


8. Metabolic changes in skeletal muscle and blood of greyhounds during 800-m track sprint.

The aim of this study was to examine some metabolic properties and changes that occur in skeletal muscle and blood of greyhounds after an 800-m sprint. Three prime moving fast-twitch muscles were selected: biceps femoris (BF), gastrocnemius (G), and vastus lateralis (VL). The amount of glycogen utilized during the event was 42.57, 43.86, and 42.73 mumol glucosyl units/g wet wt, respectively. Expressed as a function of race time (48.3 +/- 0.7 s, n = 3), the mean rate of glycogen breakdown was 53.48 +/- 0.5 mumol.g wet wt-1.min-1 during the sprint. This is equivalent to an ATP turnover of 160 mumol.g wet wt-1.min-1, assuming 100% anaerobic conversion to lactate. This represents a conservative estimate, since greyhound muscle is heterogeneous and comprised of a large percentage of fast-twitch oxidative fibers (Armstrong et al., Am. J. Anat. 163: 87-98, 1982). The large decrease in muscle glycogen was accompanied by a 6- to 7-fold increase in muscle lactate from 3.48 +/- 0.13 to 25.42 +/- 3.54 (BF), 2.54 +/- 1.05 to 18.96 +/- 2.60 (G), and 4.57 +/- 0.44 to 30.09 +/- 1.94 mumol.g wet wt (VL), and a fall in muscle pH from 6.88 +/- 0.03 to 6.40 +/- 0.02 (BF), 6.92 +/- 0.02 to 6.56 +/- 0.02 (G), and 6.93 +/- 0.02 to 6.47 +/- 0.01 (VL). Cytosolic phosphorylation potential in BF decreased 10-fold from 11,360 +/- 680 to 1,184 +/- 347, and redox potential decreased 5-fold, indicating a marked reduction in the cytosol at this time.(ABSTRACT TRUNCATED AT 250 WORDS)

9. Skeletal muscle fibre composition in the dog and its relationship to athletic ability.

Skeletal limb muscles of the dog could generally be differentiated into three fibre types according to myosin adenosine triphosphatase (ATPase) (pH 9.4) and succinic dehydrogenase activities. However, because this was not always possible, for comparative purposes only, division into low myosin ATPase (slow twitch) type I and high myosin ATPase (fast twitch) type II fibres was used. The percentage of these fibre types in m deltoideus, m triceps brachii caput longum, m vastus lateralis, m gluteus medius, m biceps femoris and m semitendinosus was examined in the greyhound, crossbred and foxhound. In all muscles the greyhound had a significantly higher percentage of fibres with high myosin ATPase activity at pH 9.4 than the other breeds, with almost 100 per cent in most muscles examined. The activities of nine enzymes and glycogen concentration were determined in m gluteus medius and m semitendinosus of the greyhound and crossbred. Significantly higher levels of creatine kinase, aldolase, alanine aminotransferase and citrate synthase and significantly lower activities of 3-hydroxyacyl coenzyme A dehydrogenase and hexokinase were found in both muscles of the greyhound. The implications of these findings are discussed.

All conclusions of studies will be listed in this original post (TABLE OF SUMMARIES) for quick reference.

Every now and then people start worrying about the effect all of this intense training has on their future health. Well, studies exist, so if you find any, post them here.

1. Degenerative Changes in the Ankle in Former Elite High Jumpers

The talotibiofibular joints in former high jumpers showed only slight signs of wear and tear with no clinically relevant side-related differences; severe arthrosis with narrowing of the joint space was rare. The risk of arthrosis connected with high-jumping seems not to be elevated.

2. Association between muscular strength and mortality in men: prospective cohort study

Muscular strength is inversely and independently associated with death from all causes and cancer in men, even after adjusting for cardiorespiratory fitness and other potential confounders.

Peer Reviewed Studies Discussion / MISC Resistence Training
« on: June 04, 2009, 09:52:39 pm »
All conclusions of studies will be listed in this original post (TABLE OF SUMMARIES) for quick reference.

We could always sort these out later. Post anything related to resistance training and strength/power/etc. Examples could be effect of squatting, oly weightlifting, optimal protocols and rep ranges, speed of contraction, etc.

1. Early Phase Differential Effects of Slow and Fast Barbell Squat Training

In the long jump, the fast group was superior in numerous variables including knee peak velocity and total-body vertical and absolute power. In the vertical jump, fast training affected the ankle and hip more (e.g., average power), and slow training mostly affected the knee (average torque). In isokinetic testing, the fast group improved strength most at the faster velocities, while the slow group strength changes were consistent across the velocities tested. Although both slow and fast training improved performance, faster training showed some advantages in quantity and magnitude of training effects.

2. Neuromuscular and hormonal responses in elite athletes to two successive strength training sessions in one day

Summary  Acute neuromuscular and endocrine adaptations to weight-lifting were investigated during two successive high intensity training sessions in the same day. Both the morning (I) (from 9.00 to 11.00 hours) and the afternoon (II) (from 15.00 hours to 17.00 hours) training sessions resulted in decreases in maximal isometric strength (p<0.01 and <0.05), shifts (worsening) in the force-time curve in the absolute scale (p<0.05 and ns.) and in decreases in the maximal integrated EMG (p<0.01 and <0.05) of the selected leg extensor muscles.

3. Neuromuscular and hormonal adaptations in athletes to strength training in two years (1988)

Neuromuscular and hormonal adaptations to prolonged strength training were investigated in nine elite weight lifters. The average increases occurred over the 2-yr follow-up period in the maximal neural activation (integrated electromyogram, IEMG; 4.2%, P = NS), maximal isometric leg-extension force (4.9%, P = NS), averaged concentric power index (4.1%, P = NS), total weight-lifting result (2.8%, P less than 0.05), and total mean fiber area (5.9%, P = NS) of the vastus lateralis muscle, respectively. The present results suggest that prolonged intensive strength training in elite athletes may influence the pituitary and possibly hypothalamic levels, leading to increased serum levels of testosterone. This may create more optimal conditions to utilize more intensive training leading to increased strength development.

4. Upper body training and the triceps brachii muscle of elite cross country skiers.

The subjects who demonstrated the largest improvement in performance exhibited the largest muscle adaptation, which, in turn, was related to the pre-maximal oxygen uptake.


Contrary to popular belief and the practices of many athletes, the peer-
reviewed evidence does not support the view that such exercises are
more effective than traditional, slow and heavy weight training in
enhancing muscle power and athletic performance. In fact, such
exercises do not appear to be any more effective in this regard than
weight training at a relatively slow cadence, and some evidence
suggests they are less so. Also, such explosive exercises do not transfer
well (if at all) to athletic performance on the sports field, and present a
significant injury risk. Therefore, such exercises should not be
recommended in the strength and conditioning training of athletes,
except those who need to learn the specific skill of lifting heavy weights
fast, such as Olympic lifters and strongmen

All conclusions of studies will be listed in this original post (TABLE OF SUMMARIES) for quick reference.

This thread goes out to our dear friend CoolColJ:

Post anything related to Sleep, Biological Rhythms, or Stress and its effect on performance.

1A. Elevations in core and muscle temperature impairs repeated sprint performance

Conclusion: Although an elevated muscle temperature is expected to promote sprint performance, power output during the repeated sprints was reduced by hyperthermia. The impaired performance does not seem to relate to the accumulation of recognized metabolic fatigue agents and we, therefore, suggest that it may relate to the influence of high core temperature on the function of the central nervous system.

1. Electro-mechanical response times and muscle strength after sleep deprivation.

The results suggest that subjects who have undergone 60 h of SD can react as fast, and with as much force, as those who have had 7 h of sleep per night.

2. Physical performance and physiological responses following 60 hours of sleep deprivation.

These results suggest that sleep loss of up to 60 h will not impair the capability for physical work, a finding of considerable importance in sustained military operations which frequently involve the combination of both physical and mental tasks.

3. The effect of partial sleep deprivation on weight-lifting performance

Results indicate that submaximal lifting tasks are more affected by sleep loss than are maximal efforts, particularly for the first two nights of successive sleep restriction.

4. Effects of caffeine, sleep loss, and stress on cognitive performance and mood during U.S. Navy SEAL training

Sleep deprivation and environmental stress adversely affected performance and mood. Caffeine, in a dose-dependent manner, mitigated many adverse effects of exposure to multiple stressors. Caffeine (200 and 300 mg) significantly improved visual vigilance, choice reaction time, repeated acquisition, self-reported fatigue and sleepiness with the greatest effects on tests of vigilance, reaction time, and alertness. Marksmanship, a task that requires fine motor coordination and steadiness, was not affected by caffeine. The greatest effects of caffeine were present 1 h post-administration, but significant effects persisted for 8 h.

5. Caffeine effects on marksmanship during high-stress military training with 72 hour sleep deprivation.

Sighting time was significantly faster in sleep deprived individuals after taking 200 or 300 mg of caffeine compared with placebo or 100 mg of caffeine. No differences in accuracy measures between caffeine treatment groups were evident at any test period. CONCLUSION: During periods of sleep deprivation combined with other stressors, the use of 200 or 300 mg of caffeine enabled SEAL trainees to sight the target and pull the trigger faster without compromising shooting accuracy.

6. Sleep-dependent learning: a nap is as good as a night

Thus, from the perspective of behavioral improvement, a nap is as good as a night of sleep for learning on this perceptual task.

7. The effects of two alternative timings of a one-hour nap on early morning performance.

It was concluded that a one-hour nap could counteract the late night performance decrement.

8. Effects of Exercise, Bedrest and Napping on Performance Decrement During 40 Hours

... and naps reduce or remove this impairment. Bedrest is not a substitute for sleep.

9. Impact of Ramadan on physical performance in professional soccer players

Performance declined significantly (p<0.05) for speed, agility, dribbling speed and endurance, and most stayed low after the conclusion of Ramadan. Nearly 70% of the players thought that their training and performance were adversely affected during the fast.

10. Physical performance responses during 72 h of military operational stress.

Results: Fat-free mass (-2.3%) and fat mass (-7.3%) declined (P <= 0.05) during SUSOPS. Squat-jump mean power (-9%) and total work (-15%) declined (P <= 0.05) during SUSOPS. Bench-press power output, grenade throw, and marksmanship for pop-up targets were not affected. Obstacle course and box-lift performances were lower (P <= 0.05) on D3 but showed some recovery on D4. Wall building was ~25% lower (P <= 0.05) during SUSOPS.

11. Circadian variation in sports performance.
Atkinson G, Reilly T.

Centre for Sport and Exercise Sciences, School of Human Sciences, Liverpool John Moores University, England.

Chronobiology is the science concerned with investigations of time-dependent changes in physiological variables. Circadian rhythms refer to variations that recur every 24 hours. Many physiological circadian rhythms at rest are endogenously controlled, and persist when an individual is isolated from environmental fluctuations. Unlike physiological variables, human performance cannot be monitored continuously in order to describe circadian rhythmicity. Experimental studies of the effect of circadian rhythms on performance need to be carefully designed in order to control for serial fatigue effects and to minimise disturbances in sleep. The detection of rhythmicity in performance variables is also highly influenced by the degree of test-retest repeatability of the measuring equipment. The majority of components of sports performance, e.g. flexibility, muscle strength, short term high power output, vary with time of day in a sinusoidal manner and peak in the early evening close to the daily maximum in body temperature. Psychological tests of short term memory, heart rate-based tests of physical fitness, and prolonged submaximal exercise performance carried out in hot conditions show peak times in the morning. Heart rate-based tests of work capacity appear to peak in the morning because the heart rate responses to exercise are minimal at this time of day. Post-lunch declines are evident with performance variables such as muscle strength, especially if measured frequently enough and sequentially within a 24-hour period to cause fatigue in individuals. More research work is needed to ascertain whether performance in tasks demanding fine motor control varies with time of day. Metabolic and respiratory rhythms are flattened when exercise becomes strenuous whilst the body temperature rhythm persists during maximal exercise. Higher work-rates are selected spontaneously in the early evening. At present, it is not known whether time of day influences the responses of a set training regimen (one in which the training stimulus does not vary with time of day) for endurance, strength, or the learning of motor skills. The normal circadian rhythms can be desynchronised following a flight across several time zones or a transfer to nocturnal work shifts. Although athletes show all the symptoms of 'jet lag' (increased fatigue, disturbed sleep and circadian rhythms), more research work is needed to identify the effects of transmeridian travel on the actual performances of elite sports competitors. Such investigations would need to be chronobiological, i.e. monitor performance at several times on several post-flight days, and take into account direction of travel, time of day of competition and the various performance components involved in a particular sport. Shiftwork interferes with participation in competitive sport, although there may be greater opportunities for shiftworkers to train in the hours of daylight for individual sports such as cycling and swimming. Studies should be conducted to ascertain whether shiftwork-mediated rhythm disturbances affect sports performance. Individual differences in performance rhythms are small but significant. Circadian rhythms are larger in amplitude in physically fit individuals than sedentary individuals. Athletes over 50 years of age tend to be higher in 'morningness', habitually scheduling relatively more training in the morning and selecting relatively higher work-rates during exercise compared with young athletes. These differences should be recognised by practitioners concerned with organising the habitual regimens of athletes.


The results indicated that oral temperature, P (peak), P (mean) and P (max) varied concomitantly during the day. These results suggest that there was a circadian rhythm in anaerobic performance during cycle tests. The recording of oral temperature allows one to estimate the time of occurrence of maximal and minimal values in the circadian rhythm of anaerobic performance.

13. Sports, Sleep, and Circadian Rhythms : Circadian Rhythms and Enhanced Athletic Performance in the National Football League

Circadian rhythms produce daily changes in critical elements of athletic performance. We explored the significance of performing at different circadian times in the national football league (NFL) over the last 25 seasons. West coast (WC) nfl teams should have a circadian advantage over east coast (EC) teams during monday night football (MNF) games because WC teams are essentially playing closer to the proposed peak athletic performance time of day. Retrospectice data analysis was applied to all games involving WC versus EC teams playing on MNF with start times of 9:00 pm Eastern Standard Time (EST) from 1970-1994 seasons. Logistic regression analysis of win-loss records relative to point spreads and home-field advantage were examined. West Coast Teams win more often (p < 0.01) and by more points per game than EC teams. West Coast teams are performing significantly (p < 0.01) better than is predicted by the Las Vegas odds (the point spread). This apparent advantage enhances home-field advantage for WC teams and essentially eliminates the beneficial effects of home-field advantage for EC teams during MNF games. These results support the presence of an enhancement of athletic performance at certain circadian times of the day.

14. Diurnal Rhythm of the Muscular Performance of Elbow Flexors During Isometric Contractions

We also assessed variations in the level of maximal activity of the muscle under maximal voluntary contraction. Neuromuscular efficiency fluctuated during the day, with maximal and minimal efficiency at 18:00 h and 9:00 h, respectively, whereas activation level was maximal at 18:00 h and minimal at 9:00 h. The diurnal rhythm of torque was accounted for by variations in both central nervous system command and the contractile state of the muscle.

15. Circadian performance differences between morning and evening 'types'

significant differences were apparent with the number of items correctly rejected. M (MORNING) types' correct rejection levels were significantly better than E (EVENING) types' in the morning, whereas they were worse during the evening. Whilst E types showed a steady improvement throughout the day, M types showed a general decline. A post-lunch dip in performance was quite evident for M types, but not for E types. In addition, the circadian trends in correct rejection levels and body temperature were highly positively correlated for E types, but a significant negative relationship between these parameters was found for M types. These findings are discussed.


Despite the standardized conditions, the results showed that isometric maximal strength varied with time of day during both a submaximal exercise and at rest without prior exercise. The sine waves representing these two rhythms were correlated significantly. Although at rest the diurnal rhythm followed muscular activity (i.e., neurophysiological factors), during exercise, this rhythm was thought to stem more from fluctuations in the contractile state of muscle. (Chronobiology International, 17(5), 693-704, 2000)

17. Circadian rhythms have no effect on cycling performance


18. Time-of-day dependence of isokinetic leg strength and associated interday variability.

This finding appears to be consistent with current knowledge about time-of-day effects on the assessment of muscular strength. Thus for stable and maximal values to be obtained during isokinetic leg testing, the use of multiple-trial protocols is recommended, with testing occurring as close to 18.00-19.30 hours as possible. In addition, the observed significant time-of-day effect suggests that appropriate comparison of maximal isokinetic leg strength can only be achieved based on data obtained within 30 min of the same time of day.

19. Effects of dehydration on isometric muscular strength and endurance.

These results provide evidence that isometric strength and endurance are unaffected 3.5 h after dehydration of approximately 4% body mass.

20. Sleep deprivation induced anxiety and anaerobic performance

Neither anaerobic pa-
rameters nor state anxiety levels were affected by one night
partial sleep deprivation. Our results suggest that 30 hours con-
tinuous wakefulness may increase anxiety level without impair-
ing anaerobic performance, whereas one night of partial sleep
deprivation was ineffective on both state anxiety and anaerobic

21. The role of a short post-lunch nap in improving cognitive, motor, and sprint performance in participants with partial sleep deprivation

These results indicate that a post-lunch nap improves alertness and aspects of mental and physical performance following partial sleep loss, and have implications for athletes with restricted sleep during training or before competition.

22. Effects of One Night of Partial Sleep Deprivation upon Diurnal Rhythms of Accuracy and Consistency in Throwing Darts

Increasing time awake was associated with decreased alertness and increased fatigue, as well as slight negative effects upon performance. We conclude that the simple task of throwing darts at a target provides information about chronobiological changes in circumstances where time awake and sleep loss might affect psychomotor performance.

23. Effects of a selective sleep deprivation on subsequent anaerobic performance

The peak power, the mean power output and the peak velocity recorded after partial sleep deprivation were not modified in comparison with the values obtained after the reference night. These findings suggest that acute sleep loss did not contribute to alterations in supramaximal exercise.

24. Effects of one night's sleep deprivation on anaerobic performance the following day

Up to 24 h of waking, anaerobic power variables were not affected; however, they were impaired after 36 h without sleep. Analysis of variance revealed that blood lactate concentrations were unaffected by sleep loss, by time of day of testing or by the interaction of the two. In conclusion, sleep deprivation reduced the difference between morning and afternoon in anaerobic power variables. Anaerobic performances were unaffected after 24 h of wakefulness but were impaired after 36 h without sleep.

25. Sleep deprivation and exercise

Concerning anaerobic power and strength, significant alterations have not been found; however, for prolonged events there may be an interaction between these two factors, which suggests a protection mechanism. Nevertheless, it is important to consider that one of the main alterations caused by sleep deprivation the increase of the subjective perception, which presents a factor to decrease and compromise the physical performance per se, and may represent a masking element of the deleterious effects of sleep deprivation. Thus, the aim of present review is to discuss the different aspects of relationship between physical exercise and sleep deprivation, showing their effects and consequences in physical performance.

26. The Impact of Sleep Deprivation on Decision Making: A Review

Few sleep deprivation (SD) studies involve realism or high-level decision making, factors relevant to managers, military commanders, and so forth, who are undergoing prolonged work during crises. Instead, research has favored simple tasks sensitive to SD mostly because of their dull monotony. In contrast, complex  -based, convergent, and logical tasks are unaffected by short-term SD, seemingly because of heightened participant interest and compensatory effort. However, recent findings show that despite this effort, SD still impairs decision making involving the unexpected, innovation, revising plans, competing distraction, and effective communication. Decision-making models developed outside SD provide useful perspectives on these latter effects, as does a neuropsychological explanation of sleep function. SD presents particular difficulties for sleep-deprived decision makers who require these latter skills during emergency situations.

27. The Acute Effects of Twenty-Four Hours of Sleep Loss on the Performance of National-Caliber Male Collegiate Weightlifters

Currently, the degree to which sleep loss influences weightlifting performance is unknown. This study compared the effects of 24 hours of sleep loss on weightlifting performance and subjective ratings of psychological states pre-exercise and postexercise in national-caliber male collegiate weightlifters. Nine males performed a maximal weightlifting protocol following 24 hours of sleep loss and a night of normal sleep. The subjects participated in a randomized, counterbalanced design with each sleep condition separated by 7 days. Testosterone and cortisol levels were quantified prior to, immediately after, and 1 hour after the resistance training session. Additionally, profile of mood states and subjective sleepiness were evaluated at the same time points. The resistance training protocol consisted of several sets of snatches, clean and jerks, and front squats. Performance was evaluated as individual exercise volume load, training intensity and overall workout volume load, and training intensity. During each training session the maximum weight lifted for the snatch, clean and jerk, and front squat were noted. No significant differences were found for any of the performance variables. A significant decrease following the sleep condition was noted for cortisol concentration immediately after and 1 hour postexercise. Vigor, fatigue, confusion, total mood disturbance, and sleepiness were all significantly altered by sleep loss. These data suggest that 24 hours of sleep loss has no adverse effects on weightlifting performance. If an athlete is in an acute period of sleep loss, as noticed by negative mood disturbances, it may be more beneficial to focus on the psychological (motivation) rather than the physiological aspect of the sport.

28. Effect of sleep deprivation on tolerance of prolonged exercise

These findings suggest that the psychological effects of acute sleep loss may contribute to decreased tolerance of prolonged heavy exercise.

29. Sleep deprivation and cardiorespiratory function

Physiological responses to sub-maximal exercise showed persistence of the normal diurnal rhythm in heart rate and oxygen consumption, with no added effects due to sleep deprivation. However, ratings of perceived exertion (Borg scale) increased significantly throughout sleep deprivation. The findings are consistent with a mild respiratory acidosis, secondary to reduced cortical arousal and/or a progressive depletion of tissue glycogen stores which are not altered appreciably by moderate physical activity.

30. Caffeine Use in Sports: Considerations for the Athlete.

caffeine can be taken gradually at low doses to avoid tolerance during the course of 3 or 4 days, just before intense training to sustain exercise intensity; and caffeine can improve cognitive aspects of performance, such as concentration, when an athlete has not slept well. Athletes and coaches also must consider how a person's body size, age, gender, previous use, level of tolerance, and the dose itself all influence the ergogenic effects of caffeine on sports performance.

31. Effects of Caffeine on Prolonged Intermittent-Sprint Ability in Team-Sport Athletes.

Conclusion: This study revealed that acute caffeine ingestion can significantly enhance performance of prolonged, intermittent-sprint ability in competitive, male, team-sport athletes.

32. Maximal aerobic exercise following prolonged sleep deprivation.

The effect of 60 h without sleep upon maximal oxygen intake was examined in 12 young women, using a cycle ergometer protocol. The arousal of the subjects was maintained by requiring the performance of a sequence of cognitive tasks throughout the experimental period. Well-defined oxygen intake plateaus were obtained both before and after sleep deprivation, and no change of maximal oxygen intake was observed immediately following sleep deprivation. The endurance time for exhausting exercise also remained unchanged, as did such markers of aerobic performance as peak exercise ventilation, peak heart rate, peak respiratory gas exchange ratio, and peak blood lactate.

33. Multiple Effects of Caffeine on Simulated High-Intensity Team-Sport Performance.

The effects of caffeine on mean performance (+/-90% confidence limits) over all 14 circuits were: sprint speeds, 0.5% (+/-1.7%) through 2.9% (+/-1.3%); first-drive power, 5.0% (+/-2.5%); second-drive power, -1.2% (+/-6.8%); and passing accuracy, 9.6% (+/-6.1%). The enhancements were mediated partly through a reduction of fatigue that developed throughout the test and partly by enhanced performance for some measures from the first circuit. Caffeine produced a 51% (+/-11%) increase in mean epinephrine concentration; correlations between individual changes in epinephrine concentration and changes in performance were mostly unclear, but there were some strong positive correlations with sprint speeds and a strong negative correlation with passing accuracy. Conclusion: Caffeine is likely to produce substantial enhancement of several aspects of high-intensity team-sport performance.

Peer Reviewed Studies Discussion / Mind-Muscle Link
« on: June 04, 2009, 07:39:19 pm »
All conclusions of studies will be listed in this original post (TABLE OF SUMMARIES) for quick reference.

This is a very interesting subject, that I believe highly in. Post any studies related to mental training & it's effect on strength & performance.


The improvement in muscle strength for trained groups was accompanied by significant increases in electroencephalogram-derived cortical potential, a measure previously shown to be directly related to control of voluntary muscle contractions. We conclude that the mental training employed by this study enhances the cortical output signal, which drives the muscles to a higher activation level and increases strength.

2. Strength increases from the motor program: comparison of training with maximal voluntary and imagined muscle contractions

Together these results indicate that training-induced changes of synergist and antagonist muscle activation patterns may have contributed to force increases in some of the subjects. 7. Strength increases can be achieved without repeated muscle activation. These force gains appear to result from practice effects on central motor programming/planning. The results of these experiments add to existing evidence for the neural origin of strength increases that occur before muscle hypertrophy.

3. Can Mental Practice Increase Ankle Dorsiflexor Torque?


4. Mind, muscles and motoneurones

Mental imagery of exercise helps performance but the way in which it works is multifactional: it evokes muscle contraction sufficient to activate muscle receptors. Furthermore, it is possible for subjects to focus specifically on control of particular muscles even without feedback from them.

5. Effects of imagery motor training on torque production of ankle plantar flexor muscles

The results of this study show that imagery training of lower leg muscles significantly increased voluntary torque production of the ankle plantar-flexor muscles and that the force increase was not due to nonspecific motivational effects.

6. Effects of pretest stimulative and sedative music on grip strength.

showed that participants (N = 50) evidenced higher grip strength after listening to stimulative music (M = 43.94 kg.force) than after sedative music or a white noise control condition. Sedative music yielded lower scores than white noise.

7. The effects of synchronous music on 400-m sprint performance

This finding supported the first research hypothesis, that synchronous music would result in better performance than a no-music control, but not the second hypothesis, that performance in the motivational synchronous music condition would be better than that in the oudeterous condition. It appears that synchronous music can be applied to anaerobic endurance performance among non-elite sportspersons with a considerable positive effect.

8. Does mental practice enhance performance?

A meta-analysis of the literature on mental practice was conducted to determine the effect of mental practice on performance and to identify conditions under which mental practice is most effective. Results indicate that mental practice has a positive and significant effect on performance, and the effectiveness of mental practice is moderated by the type of task, the retention interval between practice and performance, and the length or duration of the mental practice intervention.

9. The effects of positive and negative imagery on motor skill performance

An investigation was carried out into the effect of imagery instructions on a simple motor skill accuracy task (putting a golf ball). Thirty college students were blocked on their putting ability and randomly assigned within blocks to one of three experimental conditions: (a) positive imagery, (b) negative imagery, and (c) control. Subjects in the two imagery conditions were given the identical instructions for imagining the backswing and putting stroke. In the positive imagery group, subjects imagined the ball going into the cup, while subjects using negative imagery visualized the ball narrowly missing the cup. Subjects in the control group putted without instructions. On each of 6 consecutive days a 10-putt trial was conducted for each subject. There was a significant main effect on performance improvement for the experimental manipulation. Post hoc analyses showed significant differences among all groups, with positive imagery producing the most improvement, the control condition producing less, and negative imagery resulting in performance deterioration. Results are discussed in relation to the existing literature, and future research directions are delineated.

10. Using Motor Imagery in the Rehabilitation of Hemiparesis , Archives of Physical Medicine and Rehabilitation, Volume 84, Issue 7, Pages 1090-1092

A motor imagery training program consisting of imagined wrist movements (extension, pronation-supination) and mental simulations of reaching and object manipulation making use of a mirror box apparatus. Twelve 1-hour experimental sessions were delivered, 3 times a week for 4 consecutive weeks. Performance of the paretic limb improved after the imagery intervention, indicated by increases in assessment scores and functionality and decreases in movement times. The improvements over baseline performance remained stable over a 3-month period.

11. Improvement and generalization of arm motor performance through motor imagery practice

These findings put forward the idea that mental training facilitates motor learning and allows its partial transfer to nearby workspaces. They further suggest that motor prediction, a common process during both actual and imagined movements, is a fundamental operation for both sensorimotor control and learning.

12. Muscular responses during motor imagery as a function of muscle contraction types

Thirty right-handed volunteers were asked to lift or to imagine lifting a weighted dumbbell using different types of muscle contraction, i.e. heavy concentric, light concentric, isometric and eccentric contractions.Especially, the imagined eccentric condition elicited a significant weaker muscular activity than all other conditions. In addition, the changes in the EMG pattern mirrored those usually observed during physical movement. These findings support the hypotheses of a selective effect of MI at the level of muscular activity and of incomplete inhibition of the motor command during MI.

13. Does motor imagery enhance stretching and flexibility?  

The imagery training programme resulted in selective increased flexibility, independently of the stretching method. Overall, the improvement in flexibility was greater in the imagery group than in the control group for the front split (F1,18 = 4.9, P = 0.04), the hamstrings (F1,18 = 5.2, P = 0.035), and the ankle stretching exercises (F1,18 = 5.6, P = 0.03). There was no difference in shoulders and side-split flexibility (F1,18 = 0.1, P = 0.73 and F1,18 = 3.3, P = 0.08 respectively). Finally, there was no correlation between individual imagery ability and improvement in flexibility. Psychological and physiological effects of motor imagery could explain the increase in range of motion, suggesting that imagery enhances joint flexibility during both active and passive stretching.

14. The mind of expert motor performance is cool and focused


15. Passion and performance attainment in sport

Furthermore, results differentially linked the two passions to achievement goals and subjective well-being (SWB). Specifically, harmonious passion was a positive predictor of mastery goal pursuit and SWB, whereas obsessive passion was a positive predictor of mastery, performance-approach, and performance-avoidance goal pursuit and was unrelated to SWB. Mastery goals were positive predictors of deliberate practice, which was a direct positive predictor of performance, whereas performance-avoidance goals were direct negative predictors of performance.

16. Imaging motor imagery: Methodological issues related to expertise

It is suggested that MI is more about the neurobiology of the development of motor skills that have already been learned, but not perfected, than it is about learning motor skills de novo.

17. The embodied nature of motor imagery: the influence of posture and perspective

Thus, proprioceptive information on actual body posture is more relevant for 1PP imagery processes. Results support the embodied nature of 1PP imagery and indicate possible applications in athletic training or rehabilitation.

18. Mental Imagery Inflates Performance Expectations but not Actual Performance of a Novel and Challenging Motor Task

However, imagery practice did not benefit performance as only the physical practice group performed better on the balance task compared to control.

19. Effects of Synchronous Music on 400-Metre Sprint Performance

This finding supported the first research hypothesis, that synchronous music would result in better performance than a no-music control, but not the second hypothesis, that performance in the motivational synchronous music condition would be better than that in the oudeterous condition. It appears that synchronous music can be applied to anaerobic endurance performance among non-elite sportspersons with a considerable positive effect.

20. Effects of Music on Work-Rate Distribution During a Cycling Time Trial

These results suggest that music improves cycling speed mostly in the first few minutes of a 10-km time trial. In contrast to the findings of previous research, which suggested that music lowers perceived exertion at a constant work-rate, the participants in our time trials selected higher work-rates with music, whilst at the same time perceived these work-rates as being harder than without music.

21. The effect of motivational and relaxation music on aerobic performance, rating perceived exertion and salivary cortisol in athlete males

Based on the findings,
aerobic performance during the motivational music conditions was significantly higher than the relaxation and no music treatment. Furthermore, RPE and cortisol concentration significantly were lowered five minutes after exercise for relaxation music conditions than motivational music and no music conditions. But there were no significant differences in salivary cortisol concentrations at 30 minutes after exercise between three groups.

22. Difference In Wingate Power Output In Response To Music As Motivation:

Results indicated a significant difference in anaerobic performance when using motivational music. Peak power, average power, overall anaerobic power, and the drop in power over time were all significantly different (p<.01) than when music was not used. Performance was significantly better in all categories when motivational music was present (p<.01).

Peer Reviewed Studies Discussion / *** README ***
« on: June 04, 2009, 07:00:21 pm »

This is going to be a very fun & interesting part of our forum.

This - is - the - KNOWLEDGE VAULT.

ya i know that sounds cool, thanks.

this section will be vital in spreading knowledge throughout the forum. it will become a table of contents for performance training of sorts.

anyway, you can start your own topics on various issues. the goal here is to supply relevant peer review studies. we want to keep this section "scientific", but replies can still be opinionated & discussion oriented.

the studies may get mixed up in all of the discussion, but that is why we will have all of the summaries of each study in the original post. eventually, if these threads grow out of control, there will be links to the specific posts that contain the studies, so people can easily reference them.

so basically the rules are simple, reply with a study or comment.


All conclusions of studies will be listed in this original post (TABLE OF SUMMARIES) for quick reference.

Post any study related to sprint performance (less than or equal to 100m). This could be anything from muscle groups, energy systems, limb leverages, strength, etc.

1. Breakdown of high-energy phosphate compounds and lactate accumulation during short supramaximal exercise

We concluded that 1) in short-term maximal exercise, performance depends on the capacity for using high-energy phosphates at the beginning of the exercise, and 2) the decrease in running speed begins when the high-energy phosphate stores are depleted and most of the energy must then be produced by glycolysis.

2. Neural Influences on Sprint Running: Training Adaptations and Acute Responses.

Nerve conduction velocity (NCV) has been shown to increase in response to a period of sprint training.

An increase in motoneuron excitability, as measured by the Hoffman reflex (H-reflex), has been reported to produce a more powerful muscular contraction,

 In contrast, stretch reflexes appear to be enhanced in sprint athletes possibly because of increased muscle spindle sensitivity as a result of sprint training.

Fatigue of neural origin both during and following sprint exercise has implications with respect to optimising training frequency and volume.

3. Leg power and hopping stiffness: relationship with sprint running performance.

Although muscle power is needed for acceleration and maintaining a maximal velocity in sprint performance, high leg stiffness may be needed for high running speed. The ability to produce a stiff rebound during the maximal running velocity could be explored by measuring the stiffness of a rebound during a vertical jump.

4. Stepping Backward Can Improve Sprint Performance Over Short Distances.

The results from this investigation question the advocacy of removing the false step to improve an athlete's sprint performance over short distances. In fact, if the distance to be traveled is as little as 0.5 m in the forward direction, adopting a starting technique in which a step backward is employed may result in superior performance.

5. Starting from standing; why step backwards?

The results indicate a positive contribution to the force and power from a step backwards. We advocate developing a training program with special attention to the phenomenon step backwards.

6. Influence of high-resistance and high-velocity training on sprint performance.

The HV (HIGH VELOCITY) group improved significantly in total 100 m time (P < 0.05 compared with the RUN and PAS groups (CONTROL GROUPS)). The HR (HIGH RESISTANCE) program resulted in an improved initial acceleration phase (P < 0.05 compared with PAS).

7. The optimal downhill slope for acute overspeed running. (2008)

Compared with the 4.7 degrees slope, the 5.8 degrees slope yielded a 0.10-s faster 40-yd sprint time, resulting in a 1.9% increase in speed. CONCLUSIONS: Those who train athletes for speed should use or develop overspeed hills with slopes of approximately 5.8 degrees to maximize acute sprinting speed. The results of this study bring into question previous recommendations to use hills of 3 degrees downhill slope for this form of overspeed training.

8. Effect of Elastic-Cord Towing on the Kinematics of the Acceleration Phase of Sprinting

Elastic-cord tow training resulted in significant acute changes in sprint kinematics in the acceleration phase of an MS that do not appear to be sprint specific.

9. The Effectiveness of an 8-week High Speed Treadmill Training Program on High School Athletes.


10. Leg strength and stiffness as ability factors in 100 m sprint running.

The concentric half-squats were related to 100 m (r=0.74, p<0.001) and to the mean speed of each phase (R=0.75, p<0.01). The counter movement jump was related to 100 m (r=0.57, p<0.05) and was the predictor of the first phase (r=0.66, p<0.01). The hopping test was the predictor of the two last phases (R=0.66, p<0.05). Athletes who had the greatest leg stiffness (G1) produced the highest acceleration between the first and the second phases, and presented a deceleration between the second and the third ones. CONCLUSIONS: The concentric half-squats test was the best predictor in the 100 m sprint. Leg stiffness plays a major role in the second phase.

11. Influence of strength training on sprint performance. Current findings and implications for training.

Immediately following the start action, the powerful extensions of the hip, knee and ankle joints are the main accelerators of body mass. However, the hamstrings, the m. adductor magnus and the m. gluteus maximus are considered to make the most important contribution in producing the highest levels of speed.

12. The effects of sprint running training on sloping surfaces.

Maximum running speed and step rate were increased significantly (p < 0.05) in a 35-m running test after training by 0.29 m.s(-1) (3.5%) and 0.14 Hz (3.4%) for the combined uphill-downhill group and by 0.09 m.s(-1) (1.1%) and 0.03 Hz (2.4%) for the downhill group, whereas flight time shortened only for the combined uphill-downhill training group by 6 milliseconds (4.3%)...It can be suggested that the novel combined uphill-downhill training method is significantly more effective in improving the maximum running velocity at 35 m and the associated horizontal kinematic characteristics of sprint running than the other training methods are.

13. Relationship between strength qualities and sprinting performance.

Pearson correlation analysis revealed that the single best predictor of starting performance (2.5 m time) was the peak force (relative to bodyweight) generated during a jump from a 120 degree knee angle (concentric contraction) (r = 0.86, p = 0.0001). The single best correlate of maximum sprinting speed was the force applied at 100 ms (relative to bodyweight) from the start of a loaded jumping action (concentric contraction) (r = 0.80, p = 0.0001). SSC measures and maximum absolute strength were more related to maximum sprinting speed than starting ability.

14. Sprint performance is related to muscle fascicle length in male 100-m sprinters.

Muscle thickness was similar between groups for vastus lateralis and gastrocnemius medialis, but S10 had a significantly greater gastrocnemius lateralis muscle thickness. S10 also had a greater muscle thickness in the upper portion of the thigh, which, given similar limb lengths, demonstrates an altered "muscle shape." Pennation angle was always less in S10 than in S11. In all muscles, S10 had significantly greater fascicle length than did S11, which significantly correlated with 100-m best performance (r values from -0.40 to -0.57). It is concluded that longer fascicle length is associated with greater sprinting performance.

Peer Reviewed Studies Discussion / Tendon / Muscle / Joint Stiffness
« on: June 04, 2009, 06:21:29 pm »
All conclusions of studies will be listed in this original post (TABLE OF SUMMARIES) for quick reference.

Post anything related to tendon / muscle / joint stiffness & performance. This could be anything related to different training methods & their effect on stiffness, and the effect of this training on performance (sprinting/jumping etc).

1. Influence of elastic properties of tendon structures on jump performance in humans

Although the stiffness was not significantly related to absolute jump height in either vertical jump, it was inversely correlated with the difference in jump height between the vertical jumps performed with and without countermovement. The results suggested that the stiffness of tendon structures has a favorable effect on stretch-shortening cycle exercise, possibly due to adequate storage and recoil of elastic energy.

2. Effects of isometric squat training on the tendon stiffness and jump performance

These results suggest that isometric squat training changes the stiffness of human tendon aponeurosis complex in knee extensors to act negatively on the effects of pre-stretch during stretch-shortening cycle exercises.

3. Age-related neuromuscular function during drop jumps

These different activation patterns are in line with the mechanical behavior of GM (medial gastroc) showing significantly less fascicle shortening and relative TT (tendon tissue) stretching in the braking phase in the elderly than in the young subjects. These results suggest that age-specific muscle activation patterns as well as mechanical behaviors exist during DJs.

4. Influence of leg stiffness and its effect on myodynamic jumping performance.

The leg and ankle stiffness values were higher when the contact times were shorter. This means that by influencing contact time through verbal instructions it is possible to control leg stiffness.

5. Leg stiffness primarily depends on ankle stiffness during human hopping

Thus, we conclude that the primary mechanism for leg stiffness adjustment is the adjustment of ankle stiffness.

6. Muscle performance during maximal isometric and dynamic contractions is influenced by the stiffness of the tendinous structures

Power, force, and velocity parameters obtained during the jumps were significantly correlated to tendon stiffness. These data indicate that muscle output in high-force isometric and dynamic muscle actions is positively related to the stiffness of the tendinous structures, possibly by means of a more effective force transmission from the contractile elements to the bone.

7. Effect of landing stiffness on joint kinetics and energetics in the lower extremity.

Overall, the muscular system absorbed 19% more of the body's kinetic energy in the soft landing compared with the stiff landing, reducing the impact stress on other body tissues. The ankle plantarflexors provided the major energy absorption function in both conditions, averaging 44% of the total muscular work done followed by the knee (34%) and hip (22%) extensors.

8. Effects of Plyometric and Weight Training on Muscle-Tendon Complex and Jump Performance.

Conclusion: These results indicate that the jump performance gains after plyometric training are attributed to changes in the mechanical properties of muscle-tendon complex, rather than to the muscle activation strategies.

9. 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.

10. Effects of different duration isometric contractions on tendon elasticity in human quadriceps muscles

Stiffness increased significantly for the long-duration protocol, but not for the short-duration protocol.

The present study demonstrates a greater increase in stiffness of human tendon structures following isometric training using longer duration contractions compared to shorter contractions. This suggests that the changes in the elasticity of the tendon structures after resistance training may be affected by the duration of muscle contraction.

11. Effects of isometric training on the elasticity of human tendon structures in vivo

Thus the present results indicate that isometric training increases the stiffness and Young's modulus of human tendon structures as well as muscle strength and size. This change in the tendon structures would be assumed to be an advantage for increasing the rate of torque development and shortening the electromechanical delay.

12. Effect of habitual running on human Achilles tendon load-deformation properties and cross-sectional area

The total running duration was ~43 h, distributed over 34 wk. Tendon-aponeurosis displacement during maximal voluntary contraction was unchanged. Tendon CSA also remained unchanged In conclusion, a total training stimulus of ~9 mo of running in previously untrained subjects was adequate to induce significant cardiovascular improvements, although it did not result in any changes in the mechanical properties of the triceps surea tendon-aponeurosis complex or in the dimensions of Achilles tendon.

13. Optimal muscle fascicle length and tendon stiffness for maximising gastrocnemius efficiency during human walking and running


14. On muscle, tendon and high heels

We conclude that long-term use of high-heeled shoes induces shortening of the GM muscle fascicles and increases AT stiffness, reducing the ankle's active range of motion. Functionally, these two phenomena seem to counteract each other since no significant differences in static or dynamic torques were observed.

All conclusions of studies will be listed in this original post (TABLE OF SUMMARIES) for quick reference.

Post any study regarding MUDR / Rate coding on strength, explosiveness, and performance.

1. Motor-unit discharge rates in maximal voluntary contractions of three human muscles

An argument is presented that suggests that, in response to voluntary effort, the range of discharge rates of each motor-unit pool is limited to those only just sufficient to produce maximum force in each motor unit.

2. Maximal motor unit discharge rates in the quadriceps muscles of older weight lifters.

Results: As expected, knee extension strength in the trained weight lifters (367.0 +/- 72.0 N) was significantly greater than that in the control subjects (299.9 +/- 35.9 N;P < 0.05). Motor unit discharge rates were similar in the two subject groups at the 50% MVC force level (P > 0.05), but maximal (100% MVC) motor unit discharge rate in the weight lifters (23.8 +/- 7.71 pps) was significantly greater than that in the age-matched controls (19.1 +/- 6.29 pps;P < 0.05).

3. Adaptations in maximal motor unit discharge rate to strength training in young and older adults

In response to resistance training, maximal voluntary force increased 25% in young and 33% in older subjects (P < 0.001). Maximal MUDR increased significantly (11% young, 23% older) on day 2 [F(3,36) = 2.58, P < 0.05], but in older subjects returned to baseline levels thereafter.

4. Quadriceps muscle strength, contractile properties, and motor unit firing rates in young and old men


5. Fatigue of submaximal static contractions.

The single unit EMG recordings suggest that, in sustained and repeated submaximal contractions, muscle contractile failure is compensated by recruitment of additional motor units rather than by rate coding of those already active. During intermittent contractions large increases in the surface EMG were associated with only modest increases in firing rates. In sustained contractions when the EMG was held constant the discharge rates declined in parallel with the force. In constant force contractions involving about 35% muscle contractile failure no changes in discharge rates were seen despite substantial increases in EMG.

News, Announcements, & Suggestions / Calculator's page
« on: June 04, 2009, 01:12:13 am »

Progress Journals & Experimental Routines / *** README ***
« on: June 02, 2009, 09:04:12 pm »
The keyword for this section is "progress". One thing we should all remember, is that simply performing a routine as if it were simply a mechanical process can lead to stagnation. This stagnation may not be realized for months on end due to this mechanical nature. If our goals are big, then never should we simply just perform our training as if it were some kind of daily chore. It is essential that we monitor our progress carefully, not only in the weight room. Other tests include broad jumps, RFI (single or double leg contacts for time), 5-10-5, 10+ yard sprints, single leg jumps for height or distance, med ball throws for distance, and low box depth jumps.

We named this subforum "Progress Journals" for a reason. In order to reach our goals, then we must never lose focus.


Article & Video Discussion / *** ABOUT THIS SECTION ***
« on: June 02, 2009, 12:45:26 am »
Use this section to discuss articles and videos any site. The videos to discuss in this section are to be "informative" in nature. Examples of these videos would be the Werner Gunthor video series, Holm vs Thomas series, HPCSport lectures on performance, etc... Purely entertainment-style videos have their own section:


Article & Video Discussion / ADARQUI's Instant RFD Series
« on: June 02, 2009, 12:41:48 am »

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