You have clearly confused impact and elastance, they are separate quantities. Harder surfaces are not always more elastic then softer ones. Running on concrete has higher impact force, however it gives less elastic return.
Your referral to the law of conservation of momentum does not support your argument. This law actually supports the view that mondo is more elastic then concrete, momentum causes a greater deformation of the mondo , which in return give’s greater elastic energy. You state energy returns are higher on concrete, are you referring to elastic energy or impact energy (impact value). Injuries from concrete occur because of repetitive high impacts not from high elastic return.
While I have observed the “Harvard Track phenoma” first hand, you have to ask if there is some role played by the athletes prior knowledge that the Track is alledged to have special properties…
Not at all. The stiffness is adjusted from within, not just by what the surface allows. This can be seen in the changes in leg stiffness when transitioning from one surface to another where the adjustment for surface changes over several steps; implying a neurological element. If what you were saying were true it would be instantaneous because it is just a changing relationship in compliance.
I dont know what these posts are all about, but the Harvard track is a joke. The indoor track is notoriously bad for 200m. Most NE sprinters dont even count their times at the Harvard track because it is so much slower than the other local tracks.
Having trained on it and raced on it. It is not a fast track.
Whilst all of the recent posts have been very interesting, does any coach really need to read pages of scientific research to learn that they shouldn’t be training sprinters on concrete like surfaces?
Charlie and many other coaches were recommending tempo on grass 20 years ago and I’m sure they didn’t come to that conclusion by reading a research paper.
We have only one synthetic track in Adelaide and after 10 years of use it has degenerated to a very hard surface that athletes who are forced to use it regularly, complain of soreness to joints, shins etc.
I was only stating the obvious:
When landing on a hard surface the minimum amount of deformation of the legs is determined by their maximum tension/force capability. The softer surface will permit, but not require, less deformation as you can choose to apply less than maximum force.
A detailed analysis of recent posts you will show that certain issues are not clear cut. Harder surfaces “concrete” have higher impact, yet are necessary faster. An optimum surface for speed requires some elasticity from the ground. Grass requires stiffer legs which increases stride frequency however maximal speeds won’t be developed on grass, additional leg stiffness limits max stride length. Running on a elastic “bouncy track " is the most appropriate for developing max speeds, the surface gives more elastic energy which increases max velocity. This cannot be applied to all sprinters; elastic surfaces are not beneficial if the sprinter is unable to generate forces rapidly.
OK that’s cool, but Charlie stated earlier that he hadn’t thought of training on grass in the way mentioned in this thread. One of the reasons Charlie has achieved the success and following that he has is because he is willing to look at old and new things from a different perspective.
The importance at looking at things from every angle as well as using and understanding every available piece of infromation available to you is that as a coach it allows you to refine and adapt your training methods to better suit the athlete and their circumstances. To just follow something with out sking further questions about wh it works or how it can be improved will just lead to stagnation - You may as well just go out and buy one of those cook book coaching manuals.
I’ve long felt that tempo - particularly on grass - is one of those bags of goodies that has yet to be entirely explained. I think some of the things that have been raised in this thread have gone part of the way to doing this, but I still believe there is much more to our low intensity friend.
The claim was made that the Harvard track would be fast for sprints and that coaches didn’t understand that a fast track should be softer.
Well the proof was as Dr Sprint points out- it was never fast for sprints and could never be because the full return on a soft track happens after you’ve already left contact with it at very high speeds. What’s good for the mile is one thing- sprints another. That’s the problem with testing theories on a 7mps treadmill.
Is anyone in doubt that Tokyo 1991 and Atlanta 1996 were faster for the sprints and vastly harder than average??
It’s interesting, but we are working backwards from what was done. I originally did as much tempo- and even sprints on grass for as long as possible in our climate because I knew we’d be stuck indoors for a long period and if we went to a hard surface too early, we’d have issues by March before we could get to an outdoor southern training camp.
It’s also worth wondering if, because we had April 1986 and late Nov, early Dec 1986 training camps in the Carribean, with all the sprints as well as tempo on grass, it led to better performances overall. Previous training camps had tempo on the grass but sprint work on a track.
I was taught by Harry Jerome, those many years ago, to do “finish drills” on grass to improve top speed, but I only thought, at the time, that it enforced relaxation.
Also note Trevor Graham had Tim and Justin Gatlin on grass for 60m/90m sprints in the early SPP, and that Marita Koch trained on a cinder track for much of the year.
Based on what we are thinking about the effect of sprints on grass, what is the impact on the decision about plyos??
I’d suggest it would reduce the reliance somewhat.
Thoughts??
“The claim was made that the Harvard track would be fast for sprints and that coaches didn’t understand that a fast track should be softer.
Well the proof was as Dr Sprint points out- it was never fast for sprints and could never be because the full return on a soft track happens after you’ve already left contact with it at very high speeds. What’s good for the mile is one thing- sprints another. That’s the problem with testing theories on a 7mps treadmill.
Is anyone in doubt that Tokyo 1991 and Atlanta 1996 were faster for the sprints and vastly harder than average??”
The oval and not the infield were “tuned” The 60 and Hurdles are run on the infield ala Milrose.
No question as far as the Tokyo / Atlanta reference…
I won’t re state the mechanical principles why. I conclude grass is more effective in developing acceleration & stride rating .Mondo or elastic surfaces are more effective for max speed and stride length.
Atlanta and Tokyo was not faster because of additional hardness. It was more elastic, if it was true harder surfaces are faster, then concrete or asphalt would of be faster then synthetic. We need to move from this paradigm of harder is faster and think in terms of elasticity.