Kinda off topic here, but I work with all kinds of racehorses. Sprinters and Stayers (endurance runners) are built very differently.
Sprinters have shorter legs, shorter backs, and well developed muscles, esp in the hind area. Helps with adding propulsion. Shorter legs enable faster turning and higher cadence.
Stayers are long, lean, greyhound-like, without an ounce of added weight. Long, loping, ground-eating strides are desired in a distance race.
As for big thighs, I think a big part is genetics. The collegiate women athletes in my family all had disporportionately big thighs, as do I. But hey, as long as my "engines" do what I ask and more, I can't complain about the packaging.![]()