Usain Bolt is a Jamaican sprinter who’s the current world record holder in the 100-meter and 200-meter distances. He won another 100-meter Olympic gold medal the other day, and ran a race today as well. (I’m sure most of you already know how well he did today, but I’m not going to say here, lest some poor FrontBurnervian out there is anxiously waiting to watch the tape-delayed broadcast tonight.)
Point is, the guy is fast. But is he as fast as humans can ever hope to be? The Economist has an article detailing the statistical model of a biologist that suggests human beings have nearly reached the peak possibilities of speed. Bolt’s 100-meter record, set in 2009 in Berlin, is 9.58 seconds. If this model is to be believed, the fastest we can ever expect anybody to run that race is 9.48 seconds. We’re running out of room for improvement.
Only maybe not. Peter Weyand, a physiology professor at Southern Methodist University, is cited as believing that may not be the case. His research indicates we may have untapped muscle power that the world’s greatest athlete just haven’t yet devised a technique to take advantage of. He’s shown that:
whereas the peak force which elite sprinters apply to the track is more than four times their body weight, they can squeeze even more out of their muscles. Dr Weyand found that the forces generated while athletes hopped on one leg as fast as they could on a high-speed treadmill were roughly twice as high as during running at top speed. This translated into 30% more ground force.
Since ground force is the main determinant of sprinting speed, Dr Weyand’s results imply that human muscles are capable of producing enough oomph to propel sprinters one-third faster than Mr Bolt’s 2009 record.
The reason they have not is that in the normal, two-legged gait the foot is in contact with the ground for only around one-tenth of a second, 0.05 seconds less than when hopping. As a consequence, muscle fibres do not have enough time to contract to their full potential. Although tapping all this force while sprinting seems biomechanically inconceivable, there may be scope for slight alterations in training and gait, focused on increasing the peak power available to sprinters.
This isn’t the only time during these summer Olympics that Weyand’s expertise has been cited regarding athletic performance. Last week, Sports Illustrated published an article about South African Olympic runner Oscar Pistorius, controversial because he’s a double amputee who runs on a pair of carbon-fiber “Cheetah Flex-Feet.” He’s so fast on these artificial legs that the question was raised of whether they give him an unfair advantage. Â Pistorius was cleared to compete in international track events against able-bodied competitors, in part thanks to research done at a lab run by Weyand at Rice University.
Only thing is, when the full study was completed, Weyand actually came out publicly saying that the Cheetah legs must definitely give Pistorius an advantage.
In 2000, Weyand and a team of researchers at Harvard showing that humans, from couch potatoes to pro sprinters, have essentially the same leg-swing times when they achieve their maximum speed. Says Weyand, “The line we use around the lab is, From Usain Bolt to Grandma, they reposition their limbs in virtually the same amount of time.”
But Pistorius’s leg-swing times, when measured on a high-speed treadmill, were off the human charts. At top speed, he swings his legs between strides in 0.284 of a second, which is 20 percent faster than intact-limbed sprinters with the same top speed. “His limbs are 20 percent lighter,” Weyand says, “and he swings them 20 percent faster.”
This is important because it allows Pistorius to circumvent a main requirement of top level sprinting: putting high forces into the ground quickly. Because Pistorius can make up time with his rapid leg swing, he can leave his foot in contact with the ground longer than other sprinters. To attain the same speed, Pistorius applies lower forces — about 20 percent lower –Â , instead of higher forces over a briefer time. In this he’s like a cross-country skier, whose boot has a hinge at the toe that allows him to leave the ski down and continue to push, prolonging the time he can continue to apply force.
Of course, then Pistorius didn’t even qualify for the final of the 400-meter event. So what does Weyand know? Â (I kid, I kid)
