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Overload / Underload Training

Overload / Underload training is a style of training designed to help an athlete become faster or more powerful in their respective sport. It was first used by the Soviet Union in the 1970s to help train their Olympic track athletes. More specifically their throwing athletes, (i.e. javelin, discus, hammer throw, shot put). They found by throwing heavier objects the athletes became stronger, and then by throwing lighter objects they became faster. The combination between speed and power translated into faster and farther throws.

It was also discovered that the correct range to train with heavier or lighter was about 20%. This is because you can still keep the body’s mechanics relatively the same while training heavier or lighter. If you train with objects that are too heavy or too light, then the mechanics of the action you are training begins to break down.

This same type of overload / underload or resisted / assisted training has been able to be applied across most sports. In baseball this training has been able to be applied to both throwing and the swing. Here at ExploSwing we care more about how to train the swing with overload / underload. By swinging heavier and then lighter bats with maximum intent you will be able to build and maintain faster bat speed and exit velocity over time. Check out the ExploSwing Stack Bat System here.


Another way to overload and underload the swing is with resistance bands. Here we resist and assist the hips and lower half of the body to build more speed and power. Check out the ExploSwing Power Band System here.

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