One illustrative example of the static tension in muscle fibers during isometric exercises is the way a hand might grip a stress ball or cup without moving it. Isometric exercises similarly cause tension in muscle fibers but they do so without causing the muscle to change length. This tension is caused by myosin cross-bridge cycling and a protein called actin. Muscle fibers resist outside forces and enact bodily movements using tension. In isometric exercises, however, there is no change in the length of the muscle. This movement is called an “eccentric” muscle contraction. When the barbell is extended, the bicep lengthens. This is called “concentric” and it is really an isotonic contraction. As the barbell moves toward the shoulder in a biceps curl, the bicep shortens. Think of the motion a bicep undergoes in a standard biceps curl or that of the calf in a calf raise. Exercises that cause muscle fibers to stretch are called isotonic exercises. To discern the difference between isometric exercises and other kinds of exercise, it helps to understand how each causes muscle fibers to move.
( Note: Want our elite trainers to teach you isometric exercises, plyometric exercises and more? Start your Fitplan free trial today!) Use this article as a guide to isometric training so you can add static strength training to your workout routine today. To work them into an existing workout routine or weight loss and exercise plan, it helps to understand exactly why isometric exercises are so effective as strength training. Adding weights or resistance belts will help make them even more effective. Isometric exercises for the upper and lower body are used in rehab and physical therapy and as static strength training. These workouts, referred to as isometric exercises, are great for strength training and especially effective for people with chronic conditions or injuries for whom the explosive movement of plyometric exercises or standard fitness routines aren’t possible. Static exercises like wall sits, side planks, and body holds help build strength, shorten muscles’ recovery period, strengthen muscle fibers, and build core strength.