Details' August cover star, Olympic swimmer Michael Phelps, has built a career on his physique—which is as much the result of hard training as it is of biology. The man just has great genes. Here, a look at some of his most impressive physical stats.
6'4" —Helps him reach the wall first.
195 lb—Need to balance this number with strength to pull through the water quickly.
6'7"—Generally arm span equals height; his abnormally wide span gives him the ultimate butterfly build.
30"—More akin to someone eight inches shorter—which means less body mass to pull through the pool.
14—not freakish, but large.
He's double-jointed, meaning he has hyperextension and flexion in his ankles and knees, so his feet work like flippers that generate more force with every kick.
Strength to Body Mass:
The pull-up is the gold standard in swimming. Great swimmers can do 20. Phelps' max: 34.
Resting Heart Rate:
38. Average men are 60 to 80; athletes, 40 to 60. The bigger, stronger, and fitter your heart, the more efficient it is at pumping blood, and the lower the number.
Approximately 5.6 millimoles—Phelps recycles lactic acid (the byproduct of anaerobic metabolism) for energy better than nearly everyone in the world. Though his camp keeps specific numbers locked up, a few now-legendary stats leaked in '03, showing that after he set the world record in the 100m butterfly, his blood lactate was a measly 5.6 millimoles, little over half that of other elite swimmers. His trainers concede that number is a bit higher now. But he's "still in the top 99.8 percentile in the world," says Phelps' trainer Keenan Robinson.