From Scientific American:
If he does, some scientists believe he may close the record books for good.
Whereas myriad training techniques and technologies continue to push the boundaries of athletics, and although strength, speed and other physical traits have steadily improved since humans began cataloguing such things, the slowing pace at which sporting records are now broken has researchers speculating that perhaps we’re approaching our collective physiological limit—that athletic achievement is hitting a biological brick wall.
Common sense tells us that of course there are limits to athletic achievement: Barring some drastic amendment to the laws of physics, no human will ever run at the speed of sound. And physiologically speaking there’s only so much calcium that can flood into a muscle cell causing it to contract; there’s only so much oxygen our red blood cells can shuttle around.
In this vein, in 2008 running enthusiast and Stanford University biologist Mark Denny published a study attempting to determine if there are absolute limits to the speeds animals can run. To do so he analyzed the records of three racing sports with long histories of documentation: track and field and horse racing in the U.S., along with English greyhound racing.
By plotting winning race times back to the turn of the 20th century and by controlling for population growth, Denny was able to conclude that there is indeed a predictable limit to the time it takes for a particular species to cover a certain distance. In fact, his data show that horse and dog racing as well as some human track and field events may already be there. “We’re definitely plateauing,” Denny says. “Just look at the horse racing data, which I think parallels what’s happening in humans. Winning times in the Triple Crown haven’t really [improved] since the 1970s—and this is despite all of the millions of …