Baseball doughnut

Researchers have found that muscle contractions are stronger after reaching near maximal loads.

One research study also found that additional weight added to the bat may strengthen the muscles of the forearms and wrists.

[2] Baseball doughnuts are based on the theory of complex training, which alternates the use of heavier and lighter weights to increase explosive power.

The player in the on-deck circle normally swings a bat and stretches to prepare for their at-bat.

The doughnut is discarded in the on-deck circle when the player moves into the batter's box.

[4] Researchers claim the use of a baseball doughnut can change the muscles recruited and therefore creates inefficient hitting mechanics.

The length of time between warming up with a baseball doughnut and swinging at a pitch also seems to have an effect.