Track and field athletes have a couple different options for warming up before training or competition. One popular protocol involves dynamic stretching, and a study published in the International Journal of Sports Medicine recently tested its potential on 12 healthy volunteers.
 

Subjects applied four 30-second sets of dynamic stretching to ankle joints. Measurements taken before and after the warm up showed increased range of motion immediately after stretching. The effect lasted for 15 minutes without changing the mechanical properties of muscle tendons.