Adarq.org
Performance Area => Strength, Power, Reactivity, & Speed Discussion => Topic started by: Raptor on April 03, 2011, 03:53:20 pm
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We always hear about the reactive effect as being a spring like movement etc, but let's talk about a countermovement jump vs a paused jump. A countermovement jump will usually be higher.
In my opinion, the only real difference is not a spring like effect of any kind, the only difference in reality is the fact that the muscles get loaded more because the body weight increases as you lower and stop yourself from lowering.
The same thing occurs in a high vs even higher speed plant. The faster you go, the more strength you need to amortizate your body because your bodyweight * acceleration (plant speed) = the total amount of weight that needs to be amortizated. And if you can take in that weight, the muscles (previously enabled eccentrically to stop you from crushing into the ground) remain activated for the concentric part of the movement too, if it's done quickly.
I think that's all there is to it in reality. I keep on hearing about all this "spring" thing and I think that's erroneous and makes people fail to understand the real thing that is going on.
Now the only counter-example to this is the Olympic lifter that jumps a lot from a standstill and sucks coming off a run. I think in that situation it's a matter of technique (where technique = failing to understand/apply the proper body position to produce the maximum amount of force, and to be the most easy to amortizate, from). Also, the adaptations over time for the O-Lifters require them to generate "standstill" acceleration from a horizontally neutral position, hence their preferred "stopped" position for developing power.
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Kind of agree here... so let's apply this knowledge:
Doing plyos will allow you to jump higher from a standstill only because you'll be able to amorzize the force from just *dropping faster* then (because dropping faster will load the muscles more).
Therefore, if we were to utilize a paused jump in which we are externally loaded to the moment right up until our feet leave the ground, and then release that external load, we would jump just as high as we did if that same load was achieved through a plyometric loading instead of an external type loading (but that might be impossible to simulate because the load achieved with a plyometric movement, isn't static; it's dynamic).
And I never really understood the argument that a plyometric movement produces more force only because you're putting your limbs in a better position.. you can easily test that, wtf, it's such a stupid claim.
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Well jumping with the legs a bit foward than just straight underneath you gives you some better leverage indeed.
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Now the only counter-example to this is the Olympic lifter that jumps a lot from a standstill and sucks coming off a run. I think in that situation it's a matter of technique (where technique = failing to understand/apply the proper body position to produce the maximum amount of force, and to be the most easy to amortizate, from). Also, the adaptations over time for the O-Lifters require them to generate "standstill" acceleration from a horizontally neutral position, hence their preferred "stopped" position for developing power.
If you train to be damn explosive from a standstill then your SVJ will be better and make your RVJ looks "worse" compared to someone who isn't as good at SVJs. Doesn't necessarily mean RVJ technique is any worse.
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Now the only counter-example to this is the Olympic lifter that jumps a lot from a standstill and sucks coming off a run. I think in that situation it's a matter of technique (where technique = failing to understand/apply the proper body position to produce the maximum amount of force, and to be the most easy to amortizate, from). Also, the adaptations over time for the O-Lifters require them to generate "standstill" acceleration from a horizontally neutral position, hence their preferred "stopped" position for developing power.
If you train to be damn explosive from a standstill then your SVJ will be better and make your RVJ looks "worse" compared to someone who isn't as good at SVJs. Doesn't necessarily mean RVJ technique is any worse.
Yeah, it bridges the gap between the maximum voluntary power and maximum involuntary power... but I think these people will automatically favor a standing VJ vs a running or dropstep VJ.
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We always hear about the reactive effect as being a spring like movement etc, but let's talk about a countermovement jump vs a paused jump. A countermovement jump will usually be higher.
In my opinion, the only real difference is not a spring like effect of any kind, the only difference in reality is the fact that the muscles get loaded more because the body weight increases as you lower and stop yourself from lowering.
The same thing occurs in a high vs even higher speed plant. The faster you go, the more strength you need to amortizate your body because your bodyweight * acceleration (plant speed) = the total amount of weight that needs to be amortizated. And if you can take in that weight, the muscles (previously enabled eccentrically to stop you from crushing into the ground) remain activated for the concentric part of the movement too, if it's done quickly.
I think that's all there is to it in reality. I keep on hearing about all this "spring" thing and I think that's erroneous and makes people fail to understand the real thing that is going on.
Now the only counter-example to this is the Olympic lifter that jumps a lot from a standstill and sucks coming off a run. I think in that situation it's a matter of technique (where technique = failing to understand/apply the proper body position to produce the maximum amount of force, and to be the most easy to amortizate, from). Also, the adaptations over time for the O-Lifters require them to generate "standstill" acceleration from a horizontally neutral position, hence their preferred "stopped" position for developing power.
raptor, you just described how a spring works......................
derp
http://en.wikipedia.org/wiki/Hooke%27s_law
Hooke's law of elasticity is an approximation that states that the extension of a spring is in direct proportion with the load applied to it.
so improving runup speed, cmj, etc, all result in more load being applied to the springs, ie tendons.. if you're too weak for the load you're applying, ie, runup is too fast for your strength levels, your cns will inhibit you so that you cannot load the springs (tendons) as you are trying to do... if you are strong enough however, then the faster the runup, generally the more capability for elastic return from the tendons.
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Well my point was it's still muscle-dependent and not tendon dependent. Tendon stiffness comes into play only if you have the strength to make that happen. And I still feel it's not a tendon matter but a muscular one, as the MUSCLES will be able to generate more power sensing you're "heavier" because of the acceleration to the ground.
So it comes down to the muscle and not the tendon.
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Well my point was it's still muscle-dependent and not tendon dependent. Tendon stiffness comes into play only if you have the strength to make that happen. And I still feel it's not a tendon matter but a muscular one, as the MUSCLES will be able to generate more power sensing you're "heavier" because of the acceleration to the ground.
So it comes down to the muscle and not the tendon.
first hit on google scholar:
http://www.springerlink.com/content/v885622121616054/
"These results suggested that (1) the greater jump height in CMJ could be explained by both the tendon elasticity and the increased activation level of muscle, (2) tendon elasticity played a more significant role in the enhancement of jump height during DJ, and (3) joint stiffness was not related to either pre-stretch augmentation or tendon stiffness. "
dude, please go read pubmed studies/supertraining/science & practice before telling us theories that are conclusively debunked by thousands of peer reviewed research studies.. CMJ is less contribution from tendon than DJ, sure, but it's more contribution from tendon than static VJ.. leverage is much better in a CMJ than in a static VJ, that plays a huge part also.. if you wanted to truly compare static VJ to CMJ, you'd have to have someone who is well trained in static VJ in the first place.
bottom line, as velocity increases, tendon contribution increases, there's no way around it.
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SPANKED!
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So it comes down to the muscle and not the tendon.
When it comes to sprinting muscle can't compete with tendon elasticity.
Original Link: http://maximum-maximorum.com/2009/02/13/strength-qualities-of-the-100m-sprinter/
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bottom line, as velocity increases, tendon contribution increases, there's no way around it.
So by what means should we be using to optimally develop the tendons?.
ISO's?.
(http://maximum-maximorum.com/wp-content/uploads/2010/06/Muscle_Actions.gif)
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bottom line, as velocity increases, tendon contribution increases, there's no way around it.
So by what means should we be using to optimally develop the tendons?.
ISO's?.
isos? why isos?
reactive work.. rebounds (plyos/hops/bounds etc), jumps, sprints.
pc
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isos? why isos?
reactive work.. rebounds (plyos/hops/bounds etc), jumps, sprints.
What about the diagram above (Muscle actions & energy contribution)?. Stating an isometric contraction leads to greater energy store in the tendons as opposed to concentric/eccentric contractions which store less?.
Do plyos/hops/bounds cut it optimally considering poor form would create conconcentric/eccentric contractions?. Or would they?.
I don't mind doing ISO's at all, as long it's doing my tendons good.
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isos? why isos?
reactive work.. rebounds (plyos/hops/bounds etc), jumps, sprints.
What about the diagram above (Muscle actions & energy contribution)?. Stating an isometric contraction leads to greater energy store in the tendons as opposed to concentric/eccentric contractions which store less?.
Do plyos/hops/bounds cut it optimally considering poor form would create conconcentric/eccentric contractions?. Or would they?.
I don't mind doing ISO's at all, as long it's doing my tendons good.
Thats a dead end road youre looking at going down man, trying to target tendons specifically with isos instead of training movements/muscles is a terrible idea and it never works out for anyone. If youre getting stronger, training explosively, jumping, sprinting/doing reactive/plyo work, all that will take care of itself. Trying to isolate tendons, especially with isos is not a good idea, it may sound good in theory, but in the real world, it just doesnt pan out.
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Thats a dead end road youre looking at going down man, trying to target tendons specifically with isos instead of training movements/muscles is a terrible idea and it never works out for anyone. If youre getting stronger, training explosively, jumping, sprinting/doing reactive/plyo work, all that will take care of itself. Trying to isolate tendons, especially with isos is not a good idea, it may sound good in theory, but in the real world, it just doesnt pan out.
Check this out. Thoughts on the %'s?.
Original Link: http://journals.lww.com/nsca-jscr/Abstract/2007/08000/Plyometric_Vs_Isometric_Training_Influences_on.55.aspx
Plyometric Vs.Isometric Training Influences on Tendon Properties and Muscle Output.
Abstract.
The purpose of this study was to concurrently determine the effect that plyometric and isometric training has on tendon stiffness (K) and muscle output characteristics to compare any subsequent changes. Thirteen men trained the lower limbs either plyometrically or isometrically 2-3 times a week for a 6-week period. Medial gastrocnemius tendon stiffness was measured in vivo using ultrasonography during ramped isometric contractions before and after training. Mechanical output variables were measured using a force plate during concentric and isometric efforts. Significant (p < 0.05) training-induced increases in tendon K were seen for the plyometric (29.4%; 49.0 < 10.8 to 63.4 < 9.2 N[middle dot]mm-1) and isometric groups (61.6%; 43.9 < 2.5 to 71.0 < 7.4 N[middle dot]mm-1). Statistically similar increases in rate of force development and jump height were also seen for both training groups, with increases of 18.9 and 58.6% for the plyometric group and 16.7 and 64.3% for the isometric group, respectively. Jump height was found to be significantly correlated with tendon stiffness, such that stiffness could explain 21% of the variance in jump height. Plyometric training has been shown to place large stresses on the body, which can lead to a potential for injury, whereas explosive isometric training has been shown here to provide similar benefits to that of plyometric training with respect to the measured variables, but with reduced impact forces, and would therefore provide a useful adjunct for athletic training programs within a 6-week time frame.
(C) 2007 National Strength and Conditioning Association
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isos? why isos?
reactive work.. rebounds (plyos/hops/bounds etc), jumps, sprints.
What about the diagram above (Muscle actions & energy contribution)?. Stating an isometric contraction leads to greater energy store in the tendons as opposed to concentric/eccentric contractions which store less?.
Do plyos/hops/bounds cut it optimally considering poor form would create conconcentric/eccentric contractions?. Or would they?.
I don't mind doing ISO's at all, as long it's doing my tendons good.
isometric training occurs in virtually every movement known to man.. picture a heavy barbell squat, a depth jump, etc.. eccentric -> isometric -> concentric.. if you want to train isometrically, increase intensity on the core lifts, core ballistic exercises, etc.. for example, going heavier on squat, adding more sets, etc.. A near-max single is considered quasi-isometric because of the speed at which it occurs, ie, any time you lift very heavy, bar speed decreases and the movement becomes a series of isometric contractions along the various "sticking points", this causes alot more pull on the tendons... For ballistics, raising box height on depth jumps, incorporating single leg bounding, etc.. if you want to improve tendon strength & structure, improve your ballistic-training volume & overall progression (rebounds & sprints), this means learning to bound, becoming proficient at DJ's/stiff leg pogos, etc.. every time you "impact", there will be a massive eccentric contraction which causes the tendon to elongate and store energy.. Stiff leg reactive work (stiff leg ankle hops/pogos) are insanely intense on the tendons.. if you are consistent with reactive work, you will definitely improve tendon strength & structure, and thus be more spring-like.. you don't need focused isometric work to achieve the gains you want.. that type of training is largely academic and has hardly had any success in the "real world".. if it was effective, you'd see more people utilizing it by now & the inno sport forum wouldn't have died.
if you're going to incorporate various types of isometric training, i'd make sure it is very much supplementary.. if you implement isos as your core training protocol, you will waste alot of time that could have been better spent improving your core {squat, lunge, calve raise, ghr, etc} lifts.
pC
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Thats a dead end road youre looking at going down man, trying to target tendons specifically with isos instead of training movements/muscles is a terrible idea and it never works out for anyone. If youre getting stronger, training explosively, jumping, sprinting/doing reactive/plyo work, all that will take care of itself. Trying to isolate tendons, especially with isos is not a good idea, it may sound good in theory, but in the real world, it just doesnt pan out.
Check this out. Thoughts on the %'s?.
Original Link: http://journals.lww.com/nsca-jscr/Abstract/2007/08000/Plyometric_Vs_Isometric_Training_Influences_on.55.aspx
Plyometric Vs.Isometric Training Influences on Tendon Properties and Muscle Output.
Abstract.
The purpose of this study was to concurrently determine the effect that plyometric and isometric training has on tendon stiffness (K) and muscle output characteristics to compare any subsequent changes. Thirteen men trained the lower limbs either plyometrically or isometrically 2-3 times a week for a 6-week period. Medial gastrocnemius tendon stiffness was measured in vivo using ultrasonography during ramped isometric contractions before and after training. Mechanical output variables were measured using a force plate during concentric and isometric efforts. Significant (p < 0.05) training-induced increases in tendon K were seen for the plyometric (29.4%; 49.0 < 10.8 to 63.4 < 9.2 N[middle dot]mm-1) and isometric groups (61.6%; 43.9 < 2.5 to 71.0 < 7.4 N[middle dot]mm-1). Statistically similar increases in rate of force development and jump height were also seen for both training groups, with increases of 18.9 and 58.6% for the plyometric group and 16.7 and 64.3% for the isometric group, respectively. Jump height was found to be significantly correlated with tendon stiffness, such that stiffness could explain 21% of the variance in jump height. Plyometric training has been shown to place large stresses on the body, which can lead to a potential for injury, whereas explosive isometric training has been shown here to provide similar benefits to that of plyometric training with respect to the measured variables, but with reduced impact forces, and would therefore provide a useful adjunct for athletic training programs within a 6-week time frame.
(C) 2007 National Strength and Conditioning Association
Yea man, I have seen tons of studies on isos and tendon training, the problem is what actually works in theory and what happens in the real world. If tendon training and stiffness were so important, why are the 100m sprinters faster than the 200 and 400m guys? One thing you have to remember about stiffness, JOINT stiffness is what matters, which is a combination of tendon stiffness AND MUSCULAR STIFFNESS.
I know it sounds good looking at the studies to want to target tendons specifically with isos, and many people have gone down that path, most of them quit training after they lost most of their athletic ability or spun their wheels for years. As far as the study pasted, what those athletes had been doing prior to the testing has to be taken into consideration, as well as what wouldve happened over a longer time frame. Isos can have their place being a MINUTE part of a well structured plan, but focusing on training tendons and stiffness and spending most your time on them is going to put you on a one way street to nowhere.
Go look at the extreme iso threads on here for a start, it sounds great when described by schroeder and adarqs pal colbert, but in reality its just a bunch of pseudo science pushed as a golden ticket to elite athleticism. People dont want to believe that its hard to get fast, to jump high, they want to believe there is something magical out there that they arent doing, that they will stumble on and all of a sudden become elite. Thats where the isos, arp, strength shoes, etc. etc. come in and mislead people, its what theyve been waiting to hear, but in reality, its nothing more than a good activation/positional/flexibility exercise that will have a very minute strength effect IF the athlete is at a low level of strength. Train movements, train explosively and progressively. If you want to include isos thats perfectly fine and there is a place for them, but it should make up about 1% of your total program.
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Elastic tendons let ostriches run faster using less calories.
Original Link: http://www.beginrunning.com/fitness/elastic-tendons-ostriches-run-faster-less-calories/#axzz1Dv93vREe
Runners are about to suffer from a new condition. Ostrich Envy is likely to spread now a study just published has found why ostriches burn less calories than humans while running. Assistant Professor Jonas Rubenson of the Biomechanics Group in UWA’s School of Sport Science, Exercise and Health used reflective markers on limbs to capture movement. Subjects consisted of five human males and five tame ostriches although only two of them “were amenable to the procedures required for full three-dimensional gait analysis.” The study doesn’t mention how researchers discovered which were amenable but perhaps some poor undergrad volunteered to stick reflective markers on three intractable ostriches. The human subjects ran at a comfortable speed they chose themselves and trials where ostrich and human speeds matched were analyzed.
Although humans and ostriches use similar amounts of energy when walking, one aim of the research was to find why humans use 50 percent more calories than ostriches when running. Rubenson was surprised to find both groups used comparable amounts of mechanical power to swing the limbs at the same sort of speeds. Although we share similar limb mass, ostriches have a lower limb moment of inertia and the research cited recent studies showing approximately 20-30 percent of the metabolic cost of running is used for limb swing.
It seems the secret to ostriches efficient running style is their tendons which store and release much more elastic energy than our own. This occurs during the stance phase, the point when one foot is in contact with the ground while the other is swinging. During this time tendons act like springs, storing energy from landing then returning it for propulsion. They found ostriches can generate an amazing 120 percent more stance-phase mechanical joint power via release of elastic energy compared with humans.
The researchers discovered most of the elastic energy in the ostrich occurs the tarsometatarso-phalangeal (TMP) joint. This joint elevates the toes creating the tip-toe running and walking stance of the ostrich, whereas in humans the metatarsal bones are kept in contact with the ground. They also found the store of elastic energy allows ostriches to use 35 percent less muscular power than humans. We also have an elastic contribution to running although this occurs in the Achilles tendon and arch of the foot. The possibility of more economical force production in ostriches was suggested to explain a small part of the metabolic cost difference between species. Rubsenson said “animals such as the ostrich are specialized to run both fast and remarkably economically” using tendons “to store and return twice as much elastic energy per step than us, reducing the work required by their muscles.”
One group of humans that may be close to ostriches are barefoot runners. Although humans and ostriches appear to have similar ground reaction forces when running, the vertical component of the ground reaction force didn’t exhibit a transient at foot contact in ostriches. This has also been observed in barefoot runners and runners with mid and fore foot strike. The researchers suggest the lack of a vertical ground force transient could be because ostriches don’t heel strike. Ostrich feet also look more scary than VFF’s, but this probably has no effect on their running efficiency.
If you still haven’t got ostrich envy then consider this. The research was performed with subjects running at around 7 mph since at this speed ostrich and human gait is similar. But ostriches can run at speeds of 37mph compared to our sedentary 18mph. Even Usain Bolt couldn’t keep up, having hit just under 28mph over 20 meters of the 100 meter sprint. It’s possible that at faster speeds ostriches are even more efficient since other muscles may add to the elastic energy!
Rubenson hopes to use knowledge gained in the UWA lab for improving human health and performance and sees this study as having a role in development of better prosthetics and bioinspired robotics. He says his future work aims to apply information from the Lab to “technologies for enhancing human gait, such as improving locomotor economy and reducing muscle injuries”. Ultrarunners will be paying close attention as they’re already at the cutting edge when it comes to bioengineering. With ostrich feet for inspiration maybe toenail removal is just the beginning. As Rubenson says “It’s all in the spring of their step!”
Put some of these badboys in your forum banners.
(http://animal.discovery.com/birds/ostrich/pictures/ostrich-picture.jpg)