This Year “The dolphin kick is going to be used as a weapon in Beijing,” says Russell Mark, biomechanist manager of the US national swim team. During the last four years, Mark says the best American swimmers, including Phelps, have been especially focused on honing the technique. Engineers at George Washington University studying fluid dynamics recently calculated that more than 75 percent of the propulsive force of the dolphin kick comes from snapping the ankle. “If you have the ability to flip your ankle like a ballet dancer, you’ll get more whiplash action,” says Rajat Mittal, who has consulted with USA Swimming. The elite swimmers they’ve studied can bend their ankles beyond that of a ballerina’s pointed toe. Below: By cracking one’s body like a whip, the dolphin kick can move swimmers far faster than any surface stroke.
