Tsukuba, Japan—The underwater dolphin kick is a swimming technique in which propulsion is generated solely through the undulatory motion of the lower limbs, increasing swimmers' speed by moving the ...

From Michael Phelps' 2008 world record to the mechanics behind elite movement in the water, this segment breaks down how body proportions, lung capacity, buoyancy and flexibility influence speed.

Among the most important things an athlete can do is set goals, and with these goals come standards. Proper training, sleep, and nutrition are vital necessities for success in any sport. But balancing ...