Isometric, isotonic, and isokinetic exercises refer to the different techniques for activating and strengthening muscles. Isometric exercises, like planks, involve activating muscles with no movement.

Because they are low-impact, isometric exercises help injury recovery and relieve joint pain. Isometrics don't require equipment so you can do them just about anywhere, even on a plane.

Background Most studies of exercise-induced muscle injury have focussed on eccentric contractions, which are known to produce damage and delayed soreness. It is less well known that isometric ...