In a recent study in the JSCR: Effect of plyometric vs. dynamic weight training on the energy cost of running; researchers demonstrated that plyometrics had slightly superior effects on reductions in energy cost of running compared with dynamic weight training, leading them to render the conclusion that athletic development for the running athlete should emphasize plyometric activities.
While I definitely agree with the thought process, my next question is, “why?” Why does plyometric training improve performance better? In looking at the study, the weight training group only performed explosive concentric strength training, whereas the plyometric group performed depth jumps from a range of heights.
As I noted in a previous post, eccentric training has a litany of uses in the areas of gaining mobility, enhancing resiliency, and mitigating the speed of pronation, but I’ve really not spent much time discussing the acute value of eccentric actions from a performance perspective. These benefits are the same reason why I’m not at all surprised plyometrics reined supreme over “dynamic” weight training in the mentioned study.
Eccentric contraction has long been understood to be a very effective method for enhancing strength and power, with many suggesting that eccentric contractions are superior to concentric training. Again I ask why? What makes eccentric more powerful than concentric for enhancing certain athletic qualities?
Eccentric training induces a greater neural adaptation according to Hortobagyi et al (1996), Duclay et al (2008), and Brandenburg (2002). As less motor units are utilized in eccentric contraction, individual motor units receive proportionally greater stimulation than in concentric exercise (Linnamo, 2002). As noted previously eccentric actions may produce structural adaptations that are favorable for performance, including sarcomeres in series, meaning that each sarcomere has to contract a shorter distance to produce a desired contraction, potentially leading to shorter coupling times. Finally, drop jumping has been shown to improve the ability to utilize the SSC (duh?) that is a key player in locomotion. Research in the 1980s demonstrated that non-drop jump trained athletes were unable to effectively use eccentric loading in jumping and actually lost efficiency (Schmidtbleicher, 1987).
The point of all of this ranting being that if we are seeking to develop fast athletes, we need to ensure that we have an eccentric component. I’m not sold yet that they can only be plyometric components to training as the study suggests, but believe that we can probably get athletes to succeed with occasional focus on the eccentric component in our lifting sessions as well.
We, of course, must be smart about when we’re programming an emphasis on these types of contractions as they tend to create damage and can make athletes quite sore. I think in the early stages of SPP would be one of the better times to get these included before you transition away from maximal strength.
Regards,
Carson Boddicker
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Nice article, very well structured. If your interested in more research on the topic make sure to check out the work done by Drew Harrison (or Andrew J Harrison) and Tom Comyns from the University of Limerick.
I completely agree that the eccentric component is hugely important in training runners, however I think this eccentric component of training needs to be training completely differently for short distance v long distance. For long distance it’s more about the elastic transfer of energy through the fascial network. For the short distance runners it’s more about the RSI (reactive strength index), the ability to change quickly from an eccentric to a concentric contraction (Young, 1995).
Therefore, I completely agree with you. There must be a eccentric component to training, however, that eccentric component can be included in many different ways. Plyometrics is just one, and it is not, and should not be the only one.
Interesting statements.
Does RSI not involve energy transfer? How should the training modes differ between the two groups?
Regards,
Carson Boddicker
Good questions. I’ve had to think about this for a few days in order to, hopefully, come up with a decent answer.
Firstly, yes, everything that involves the SSC has an energy transfer element to it. As far as I can tell how this occurs is still up for debate. Maybe it’s the facial network, maybe it’s the elastic component of the tendon complex, maybe it’s the elastic element of the tail region of the thick filament (myosin), maybe it’s a greater neural adaptation, maybe it’s all that combined and more. But, regardless of how this “energy transfer” is occurring we know that it occurs.
The point that I’m trying to make is that the speed of this energy transfer is hugely different from sprinters to distance runners. Maybe the energy transfer during sprinting relays more on the neural adaptation, and maybe the energy transfer during distance running relays more on the fascial network. I really don’t know. But I don’t think that it really matters.
When it come to training I’m a big fan of specificity. Now days this seems to be called “functional training”, but at the end of the day it’s really just specificity. Therefore, if we know that this energy transfer is faster in sprinters, then a sprinters training program should have a element in it that’s all about trying to make this energy transfer as fast as possible.
Likewise, a distance runners energy transfer during the SSC is slower. Therefore. I feel that a distance runner does not need to do train rapid energy transfer. They need to focus on a slower energy transfer that reflects their sport.
The main reason that I think that this is important is because I feel that the physiology behind this energy transfer is different during high speed, medium speed, and low speed energy transfer. This is nothing more than an educated guess. But if I’m right, you’d want to make sure that your training the right physiology behind the energy transfer and not just energy transfer in general. Specificity is key.
Cian,
Thanks for coming back for an answer. The question I have next is how do we train the two groups differently. What drills are you using for a sprinter that wouldn’t be as useful for a distance runner and vice versa?
I’m not discounting your theory, as I may have been sheep walking in the past several years training the two groups similarly, but we have to realize that the ultimate goal in all track and field and road running events is to run faster and more efficiently, thus requiring a more efficient use of the SSC at increasing velocities.
What am I missing?
Thanks!
Regards,
Carson Boddicker
Having thought about it more and more over the last few days I don’t think that the difference between the two groups will be reflected in the drills that they perform. Instead, how they perform the drill should differ.
Mann et al., (1986) stated that the contact time decreased as the speed of the gait increased; “620 msec for walking to 260 msec for jogging to 220 msec for running to 140 msec for sprinting”.
Although the difference isn’t much between running and sprinting, runners still have more time in contact with the ground to generate force compared to sprinters. (Also what I find interesting is that there is twice the difference between running and sprinting (80msec), compared to jogging and running (40msec)).Therefore, if you were doing drop jumps as a drill you’d encourage your runners to spend slightly more time on the ground and try and generate more force (i.e jump higher out of the drop jump). However, if sprinters were doing the same drill maybe they should instead focus on getting off the ground as quickly as possible and not worry as much on how high they jump.
Having said that, if you wanted to train the acceleration phase of the sprint, maybe the sprints should focus on both, minimum contact time with the ground as well has maximum force generated.
All just theories.
If you wanted to do some personal research into different contact time training methodologies check out the Optojump (http://www.optojump.com/default.aspx?lang=en-US). We used it in University when we were outside of the lab and didn’t have access to a force plate. It’s very reliable, compares well to a force plate (only you don’t get the actual force generated) and a hell of a lot cheaper.
Cian – This is something I’ve really been giving alot of attention latley, however using different terminology or descriptions. Just to be clear here, when you mention a more or less rapid energy transfer are you simply referring to the short and long ammortization phases? Which is just less than 250ms (short) or greater than 250ms (long). Please correct me if i misunderstand you.
However if im following you accuratley then im glad to see you mention “educated guesses” and “theory”, simply because this is indeed a topic that can get pretty cumbersome and im not convinced anyone has a full grasp on it. Im actually thinking about doing my thesis on this very topic.
Getting to Carson’s application question – the only thing i see worth doing differently between runners of different events is programming more depth jump/hop (short ammortization training) progressions with 100m or less sprinters and programmig more standing countermovement jumps/hops progressions with sprinters of 2-400m.
We know that the longer a sprinting event lasts the role of the SSC diminishes. So in the case of distance runners im not sure how we would modify the SSC training or if it is even necessary to modify it all but instead just put them through a basic plyometric progression that is simple and safe. For example, a similar approach as to the Athletes Performance or Mike Boyle approach which is split up into 4-5 phases peaking with continuous jumps/hops. Thats just an example though.
All good comments from the two of you. Hopefully I read the conversation correctly
Carson,
You mention bringing a focus to the eccentric in weight training for athletes. Would you expand on how you would incorporate that (other than plyos)? Just thinking off the top of my head I could see an enhanced eccentric happening with forward lunges (using gravity to a greater effect), nordic (or natural) leg curls with a partner holding your feet/ankles and potentially holding additional weight (and/or if you have a glute-ham), push presses with prolonged eccentrics, bench press eccentrics, etc. What are your thoughts on incorporating them, and what types of exercises do you think best fit into that type of programming?
Thanks for the article, it’s good stuff!
Just a quick physiology question…
Why during the eccentric portion of the lift are fewer motor units activated?