Isometric exercises like wall sits, planks, and glute bridges hold the body in one position for a set period of time. Muscles are contracted and engaged, but they don’t lengthen during the exercise.

If you’ve ever held a plank, paused at the bottom of a squat or pressed your palms together in front of your chest, you’ve done an isometric exercise. Ta-da! These holds might look simple — after all, ...

If you’ve ever held a plank, paused at the bottom of a squat or pressed your palms together in front of your chest, you’ve done an isometric exercise. Ta-da! These holds might look simple — after all, ...