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.

Perform three sets of 30 to 45 seconds of walking, resting for 1 to 2 minutes between sets. The wall sit is a classic isometric exercise that burns out your quads, glutes, and core. It's a great ...