Isometrics are exercises like planks and wall sits that strengthen muscles and tone the body. Because they are low-impact, isometric exercises help injury recovery and relieve joint pain.

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.

Squats and bicep curls are good examples of exercises that cause the muscle to change length throughout the movement. But isometric training involves simply contracting your muscles, which ...