The 15th IAAF World Championships are underway, taking place this year in Beijing’s famed “Bird’s Nest” Olympic Stadium. The competition runs until Aug. 30, with athletes competing in track and field events that include race walking, pole vaulting, discuss throwing, javelin, hurdles, a heptathlon, and 100-400 meter races.

In Sight rounded up some of the best action shots from the first three days of the competition.