What is agonist and antagonist training?

Agonist and antagonist are two concepts used about working and opposeing muscles respectively. The working and opposeing muscles should preferably be equally strong. It is therefore important that you both do agonist and antagonist training.

For example, if you are training your upper body, it is important to train both the front and back musculature, otherwise you may have strong chest muscles and  weak back muscles which can lead to back injuries. Lack of antagonist training seen in some climbers is often expressed with protruding shoulders and poor forward bent posture.

The same is true when exercising finger strength and strength in your forearms on a hangboard or similar. Here you risk unilateral agonist training. Therefore, also be aware of training these opposing muscles.