快猫短视频

Enough angular momentum to go round? (Image: Walter Iooss Jr/Sports Illustrated/Getty)

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RUNNERS may be doing it all wrong. A slightly different posture could give runners and walkers a gravity-driven boost.

Most runners ignore the concept of angular momentum 鈥� essentially momentum associated with rotating, says Svein Otto Kanstad, a physicist and former competitive runner in Volda, Norway. With each footfall, a runner鈥檚 body pivots on the foot in contact with the ground and rotates forward, driving them towards the finishing line.

But most athletes don鈥檛 bring the trailing leg forwards quickly enough, says Kanstad: it is often stretched out behind when the leading leg hits the track, meaning the athlete鈥檚 centre of mass is tilted backwards and they don鈥檛 gain much forward movement from the angular momentum. Athletes should learn to pull their trailing leg through sooner, he says ().

Kanstad believes training athletes to run in this fashion would result in a rash of new records. He says retired US sprinter Michael Johnson ran this way: he has held the men鈥檚 400 metres world record since 1999.

This article appeared in print under the headline 鈥淩un faster using physics trick鈥�