[color=blue]Elite sprinters are not, however, simply improved versions of the average Sunday runner. They are physiologically different. For example, a typical human has in his skeletal muscles an equal balance of “fast-twitch” muscle fibers (quick contracting, easily fatigued muscle tissue that generates high power) and “slow-twitch” fibers (the muscle mass that uses oxygen – aerobic, rather than anaerobic), on which endurance runners rely. Slow-twitch muscle can contract for long periods of time with less fatigue, which helps some distance athletes run up to 60 mi. per day. Sprinters legs are genetically blessed with 70% fast-twitch and 30% slow-twitch muscles, which is what allows them to push off so fast and so powerfully, according to Scott Trappe, who heads the human performance laboratory at Indiana’s Ball State University and has studied sprinters’ muscles. But elite sprinters like Bolt may have even more of something that other world-class sprinters don’t: superfast-twich muscles, which perform at double the rate of regular fast-twitch muscles, creating even more force. Trappe says regular folks have 1% to 2% superfast-twitch skeletal muscle mass, but in a sprinter like Bolt, that figure may be up to 25%.
Reaching .82s per 10m and maintaining such velocity requires one to have greater elastic qualities and decreased friction (braking) impulses from ground contact which fit the description of increased ROM and stride length with shorter gct’s and not increased step rate and not greater propulsive power from muscles which would require longer ground contact times at maximal velocity, but would help him in the acceleration phase.
So my question to the Exercise Scientists who want to be quoted are as follows:
1. What is Bolt’s angular velocity from end of ground contact to beginning of ground contact on each step compared to his next 3 closest competitors?
2. What is the ROM the Hip goes through for Bolt during each step from end of ground contact to beginning of ground contact. What is the ROM during contact? What are they for his next 3 closest competitors?
3. What are Bolt’s ground contact times on each step compared to his next 3 closest competitors? The cumulative of this give’s us total flight time as well. Is it possible he has a longer ground contact, but shorter overall flight time?
4. Take a muscle biopsy and confirm this super fast twitch muscle in Bolt. Does it have a genetic component? If so, why do most sprinters of West African origins fail to break 11.0s in the 100m dash at the scholastic level? Why not a tendon biopsy? [/color]
I’m not going to answer all these as I would need a few thousand pages.
Super fast-twitch fibres? Give me a break. Biopsies have been carried out over decades now and guys like Mero would have found something significant years ago. However, like any biological stimulus, practice of contracting the muscles faster will lead to adaptation and possibly super faster twitching.
Agree with dbrande I do, tendon biopsies will reveal visual changes although a better test would be (provided it is an analysis of before training protocol and after)of the contribution by the tendon and muscle complex to force at a particular speed of contraction.
Ground contact time? Right on the money. Analyse all the sprinters in every race and matched for height and leg length the ones that continue to reduce their ground contact time as the race progresses are the fastest ones.
Hip ROM? Analyse carefully and tell me whether you see Usain’s thigh pass beyond the line of the body at top speed. Also check out Asafa during any world record performance and compare it to his “unsuccessful” bids to win World Championships and Olympic finals and tell me whether he extends his thigh beyond the line of the body at top speed.In time you’ll find that the new breed of champion sprinters are producing greater forces in the traditionally known braking phases of sprinting. Incidentally, Gatlin and Flo-Jo also had this particular skill which can be attributed purely to skill alone.
Check it out.