Image of Sport Galen Rupp compete in the men’s 10,000 meters wondered about the black tape Rupp was wearing on his shoulders, calves, and thighs.
Chappell Roan: “I Love Running. But Not Anymore.&rdquo Meb Keflezighi, promoting KT tape, a new USATF sponsor?
The answers are “no” and “no.” In fact, Rupp wasn’t wearing KT tape. Rupp’s black strips came from Nike research, which calls them AeroSwift tape. They’re supposed to reduce wind resistance and lead to faster running speeds.
Asked about the tape after his eighth consecutive national title in the 10,000 on Friday, Rupp replied: “Hey, they can’t hurt, and the Nike researchers are really nice guys, so I thought I’d help them out.”
Two nights later, Nike demonstrated the AeroSwift tape (in bright green) to a small group of track journalists. A spokesperson claimed the tape could reduce a runner’s air resistance by two to three percent.
That would be hugely significant if it resulted in a two to three percent improvement in performance. But of course it doesn’t. Air resistance plays a relatively small role in limiting running performance, especially among distance runners. The effect of air resistance on speed varies with the square of the speed of a moving body.
In other words, air resistance, also called “drag,” is much more important in fast downhill skiing than in running. That’s why skiers wear skintight suits. They also tuck themselves into a small, balled-up position to reduce surface area.
Most runners assume a tall and straight position. This maximizes air resistance but also maximizes running economy. A tuck just wouldn’t work. At least we haven’t yet seen anyone running fast in a tucked position.
In swimming, drag is so critical—water is more than 700 times as resistant as air—that the low-drag suits introduced before the 2008 Beijing Olympics were banned soon after. Swimmers in these suits, which supposedly reduced drag by eight percent, made a complete mockery of the world records. The suits were not allowed at the 2012 Olympics.
Nike’s AeroSwift technology is also being used for race numbers at the trials. In that form, it’s called an AeroBib. These are the first race bibs that are attached to uniforms with a glue rather than the traditional safety pins. Every runner who has ever run a race with wind flipping and bending his or her bib can appreciate the skin-tightness of the AeroBib.
The AeroBibs are being used by all competitors at the Nike-sponsored trials, promising a modest reduction in air resistance for all. Is this why the sprint and long jump performances have been so outstanding? It may take a while for science to answer that question.
