Are we growing super humans?
Provocative new research from Duke University shows that the fastest people on the planet, whether they are running on a track or swimming through the water, are getting bigger.
The fastest runners today on average have grown 6.4 inches since 1912 and they have shaved nearly a full second off the 100-meter dash. The same pattern was found in a wide range of competitive events where speed is the most critical factor.
So are we growing super humans? Apparently so, according to Adrian Bejan, professor of mechanical engineering at Duke, who says animals, including humans, are simply following a law of physics that dominates everything from how a river flows to how fast a human can run.
The secret, he says, lies in the economy of scale, and bigger means more efficient use of energy, especially when it comes to moving a mass at considerable speed, even if the mass is an Olympic sprinter.
OK, we all know people are getting bigger, chiefly because of better nutrition. But are we also getting faster?
Thirteen years ago Bejan developed what he calls constructal theory, a new concept in physics that he believes determines the design of everything in nature.
The theory was initially applied to fluid dynamics, or how any material moves through its environment. But in a paper published in the Journal of Experimental Biology, Bejan moved his theory into a controversial new arena. It also applies to biological systems, and just about everything else in the universe, he said in a telephone interview.
"Anything that moves, or anything that flows, must evolve so that it flows more and more easily," Bejan said, and that means that competitive sports -- where speed is everything -- will continue to be dominated by the giants who tower over the rest of us.
Anyone who reads that sentence is going to think of an exception to the rule, the little guy, or gal, who wins in the end, but Bejan said that doesn't invalidate his theory because the theory applies to that great mass of humans moving through history, not to individuals.
However, the statistics released by his office show that even if the theory applies to the collective mass, it is manifested in world records that are shattered nearly every year.
One of Bejan's students, Jordan Charles, lead author of the paper, compiled the records and physical characteristics of champions in a number of events, but in the interest of brevity only the men's 100-meter dash and the men's 100-meter freestyle swimming events were included in the study.
Beginning with the fabled Hawaiian swimmer, Duke Kahanamoku in 1912, Charles listed the time it took for each competitor to complete the race, and break the world record, along with the height, weight and slenderness of every winner through 2008. The duke, at 6 feet 1 inch tall, set the record at 61.6 seconds.
In most years thereafter, the record was broken by a man who was a little taller, a little heftier, and a little slimmer. The biggest guy was Matt Biondi, 6 feet six inches, who broke the record in 1985, 1986 and 1988, when the time was sliced to 48.4 seconds.
A new record of 47.05 seconds was set again in 2008 by Eamon Sullivan, who was only 1 inch taller than the duke. That may not seem like much of a difference, but Bejan said the overall record is clear -- as the athletes grew bigger, the records continued to fall.