As a follow-up to the most recent series of posts, you may enjoy this TED talk by David Epstein. Epstein is the author of The Sports Gene and offered the claim that kicked off those earlier posts--that he could accurately guess an Olympian's sport knowing only her height and weight.

The talk offers some additional context for Epstein's claim. Specifically Epstein describes how the average height and weight in a set of 24 sports has become more different over time:

In the early half of the 20th century, physical education instructors and coaches had the idea that the average body type was the best for all athletic endeavors: medium height, medium weight, no matter the sport. And this showed in athletes' bodies. In the 1920s, the average elite high-jumper and average elite shot-putter were the same exact size. But as that idea started to fade away, as sports scientists and coaches realized that rather than the average body type, you want highly specialized bodies that fit into certain athletic niches, a form of artificial selection took place, a self-sorting for bodies that fit certain sports, and athletes' bodies became more different from one another. Today, rather than the same size as the average elite high jumper, the average elite shot-putter is two and a half inches taller and 130 pounds heavier. And this happened throughout the sports world.

Here's the chart used to support that point, with data points from the early twentieth century in yellow and more recent data points in blue:

height-mass

Average height and mass for athletes in 24 sports in the early twentieth century (yellow) and today (blue)


This suggests that it has become easier over time to guess individuals' sports based on physical characteristics, but as we saw it is still difficult to do with a high degree of accuracy.

Another interesting change highlighted in the talk is the role of technology:

In 1936, Jesse Owens held the world record in the 100 meters. Had Jesse Owens been racing last year in the world championships of the 100 meters, when Jamaican sprinter Usain Bolt finished, Owens would have still had 14 feet to go.... [C]onsider that Usain Bolt started by propelling himself out of blocks down a specially fabricated carpet designed to allow him to travel as fast as humanly possible. Jesse Owens, on the other hand, ran on cinders, the ash from burnt wood, and that soft surface stole far more energy from his legs as he ran. Rather than blocks, Jesse Owens had a gardening trowel that he had to use to dig holes in the cinders to start from. Biomechanical analysis of the speed of Owens' joints shows that had been running on the same surface as Bolt, he wouldn't have been 14 feet behind, he would have been within one stride. 

The third change Epstein discusses is more dubious: a "changing mindset" among athletes giving them a "can do" attitude. In particular he mentions Roger Bannister's four-minute mile as a major psychological breakthrough in sporting. As this interview makes clear, Bannister attributes the fact that no progress was made in the fastest mile time between 1945 and 1954 to the destruction, rationing, and overall quite distracting events of WWII. It's possible that a four-minute mile was run as early as 1770. I wonder what Epstein's claims would look like on that time scale?