Isometric Movement

Isometric movement is a muscle contraction in your body that actually involves no movement. It is synonymous with isometric exercises, which are a form of resistance training and, when no weights are involved, are considered a static calisthenic exercise. This form of exercise has been around the fitness community for a long time and is used extensively for recovery from injuries.

Isometric Exercise

Isometric exercises, also known as static strength training, involve the contraction of a muscle or muscle group. Once contracted, the muscles are then held in place for a given length of time. During the exercise itself, the length of your muscle does not change, nor does the affected joint move. An example would be an isometric crunch. In this exercise, your abdominal muscles are contracted and held in place for between 10 and 30 seconds.

Types

There are two primary types of isometric exercises or movements. A submaximal isometric exercise involves holding a contracted muscle with less than the maximum strength of that muscle. For example, you would be performing a submaximal exercise if you held a weight steady in your outstretched arm. On the other hand, a maximal isometric exercise involves holding a contracted muscle with maximum effort. The most common example of this type of exercise would be pushing against an immovable object, such as a wall.

Benefits

Submaximal isometric exercise is generally used to maintain muscle strength and tone. However, contrary to dynamic exercise, isometrics have not been shown to effectively increase your strength, speed or performance. Maximal isometric exercise is primarily used for rehabilitation, especially where joint movement is to be avoided. In these cases, isometrics are initially used to stabilize the site of your injury, such as a rotator cuff, and maintain strength. For example, a study that appeared in “Clinics in Orthopedic Surgery” found that isometrics offered positive benefits for lateral epicondylitis of the distal humerus — or tennis elbow — if performed early in the recovery process.

Performing Isometric Exercises

Isometric exercises are measured in terms of both the length of time you hold each contraction and the number of repetitions. In general, there is no difference in outcome between using longer durations with less repetitions and using shorter durations with more repetitions. Maximal exercises are commonly performed for 15 to 20 repetitions, holding each for three to five seconds. With submaximal isometrics, the duration is usually increased and the number of repetitions decreased. Because each exercise targets specific muscles or muscle groups, you should ensure that your overall workout plan targets all of the muscles you wish to work out.

Limitations

Isometric exercises can cause a dramatic rise in blood pressure. If you suffer from hypertension or any form of cardiovascular disease, you should consult your doctor before beginning. You should always breathe during your isometric exercises, because holding your breath can increase your blood pressure further. Unlike dynamic strength training, isometrics will only maintain the strength of your muscles at the angle you perform the isometric exercise at, not for the full range of motion.