Faster top running speeds are achieved with greater ground forces not more rapid leg movements

Following on from Shane McKenzie's post (regarding Barefoot running), I've extracted one of the paragraphs for further discussion here as it touched on an important aspect of the research into fast running.

"It has been shown in high-speed motion analysis studies that too much time in the air and too much time on the ground hinder summative velocity in a runner. Time on the ground is regulated by stride rate. Time in the air is regulated by stride length. Studies by scientists have shown that for both sprinters and distance runners: reducing contact time, thus improving stride rate, is the key to improving performance. For a distance runner to reduce contact time by .02 seconds per stride would lead to marked improvement at any distance. The chief biomechanical means for achieving this reduction is to shorten the stride length, thus reducing braking forces."


The main study is the Harvard university study (circa 2000) conducted by Professor Weyand that concluded the average sprinter's time in the air is not much different from an elite level thlete. They found that ground contact, ie: the athlete's ability to apply greater support forces that contributed to an athlete's capacity to run faster.

The issue since this ground breaking research in 2000 has been what training methodologies are available to assist the athlete's ability to create a greater force so as to lessen the ground contact time. There are numerous theories about how this can be achieved and it's still inconclusive to pinpoint a specific exercise that categorically improves this.

To see the study paper, click below:

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I thought the key from that and similar studies was supposed to be that ground contact times essentially remain the same but that the magnitude of force generated across that timeframe was much higher in elite athletes?

ToM wrote:I thought the key from that and similar studies was supposed to be that ground contact times essentially remain the same but that the magnitude of force generated across that timeframe was much higher in elite athletes?

That has been my take in it as well.....ability to apply high magnitudes of force, in comparison to body weight. On watching some recent Weyand seminar dvd's, he emphasizes that no one to date is able to understand why certain athletes can apply more force in comparison to someone else's, where most factors appear equal.

In addition to this, he wasnt an advocate of arm drive being of any benefit to creating that force, nor dorsiflexion of foot....2 common coaching cues. I would like to see that applied in an outdoor environment, with weather factors etc. These studies were indoors on treadmill force plates where athletes hit the ground running for 8 continuous steps.....speed was quite high, 26mph from memory?

We tested this arm theory using Freelap - 40m fly in runs using a variety of arm drive techniques...text book, low, high, across body and nil movement. With only a small sample group the results were that all techniques were within .05 of each other (per athlete). We made an assumption that no arm drive out of blocks would most likely end in tears, so didn't attempt that.

I would have to agree with Youngy on this one. There are numerous biomechanical analysis of sprinters ranging from 10.5-10.8 speed to <10.10 that will back up this fact.

The difference between the good and the elite comes down to ground contact times. An efficient initial ground contact strike relative to a sprinters COM would result in decreased breaking forces and greater verticlal force output.

From a pure force output perspective, my beliefs are that maximum velocity is largely dependant on an athletes vertical force output, not horizontal forces.

Happy to hear other thoughts...

I recall the results of 'greatest amount of force applied, in shortest contact time' in a Weyand paper.

Personally, I feel that technique has to play a big part to play in putting the athlete in a position to apply high amounts of force......some of the interpretations of Weyand's work has been that technique is irrelevant.