What Is the Isometric Contraction?

Overview

During exercise and everyday activity, muscles perform a variety of movements. Under stress, a muscle can shorten, lengthen or stay the same. A contraction implies that the muscle shortens in response to force. There are four main types of contractions that muscles can endure, and one of them is an isometric contraction.

Definition

Muscle contractions are defined according to how they lengthen or respond to force. The four types of muscular contractions are concentric, eccentric, isotonic and isometric. Isometric exercises or training is commonly used in strength training and relates to exercises where there is no range of motion and no visible movement of the joint or muscle. Because the muscle does not move under force, its length does not change.

Benefits

The main benefits of isometric exercises are increased flexibility and strength. The concept of isometric exercises is fairly simple. You can easily target a specific muscle or group of muscles and base your progress on the amount of time you hold a particular pose. For example, if you are holding a weight overhead, start with 15 seconds and increase the time or amount of weight as you progress.

Use

Isometric exercises are commonly used in strength training, yoga and martial arts. In yoga or martial arts, isometric contractions can be a safe and effective way to hold a pose and work on balance and flexibility. With strength training, isometrics can cause more muscles to react through stabilization. For example, if you are holding a weight overhead, the abdominal and back muscles will be engaged to help stabilize the weight.

Exercises

An example of an isometric contraction is holding a heavy object over your head without moving. In this instance, the muscles in your upper body are challenged to hold the object up, but because you are not moving it, the muscles are not moving either. Isometric exercises can be done using your own body weight or free weights. Other examples include a handstand with no movement once you are up, staying in the "up" part of a push-up and pushing against something that does not move, like a wall.

Considerations

When building an exercise routine for strength training and flexibility, it's best to incorporate a variety of movements. Isometrics should be combined with dynamic or moving exercises to fully activate the joints and muscles. As with any exercise, warm up properly, start slowly and never lift more weight than you can safely handle.