Isometric exercises are tightening (contractions) of a specific muscle or group of muscles. During isometric exercises, the muscle doesn't noticeably change length. The affected joint also doesn't move. Isometric exercises help maintain strength. They can also build strength, but not effectively. And they can be performed anywhere. Examples include a leg lift or plank.

Because isometric exercises are done in one position without movement, they'll improve strength in only one specific position. You'd have to do many isometric exercises through your limb's whole range of motion to improve muscle strength across the range.

Since isometric exercises are done in a still (static) position, they won't help improve speed or athletic performance. Isometric exercises can be useful, however, in enhancing stabilization — keeping the affected area's position. These exercises can help because muscles often tighten without movement to help stabilize joints and your core.

Isometric exercises may be helpful to someone who has an injury, which could make movement painful. For instance, if you injure the rotator cuff, a health care provider or physical therapist might recommend doing isometric exercises. For example, they may suggest exercises that involve the group of muscles that helps stabilize the shoulder. This can help maintain shoulder strength during recovery.

Isometric training may also be helpful to someone who has arthritis. Arthritis could be aggravated by using muscles to move a joint through the full range of motion. As people with arthritis perform isometric exercises and improve their strength, they may progress to other types of strength training. Strength training may help reduce pain and improve physical function.

Studies have shown that isometric exercises may also help lower and control your blood pressure. Physical activity and dynamic resistance training can help lower blood pressure, too. But if you have high blood pressure, exercise at a lower level of intensity. Exercising at a higher level of intensity can cause a dramatic increase in your blood pressure during the activity.

Check with your health care provider before beginning isometric exercises if you have high blood pressure or any heart problems. Avoid holding your breath and straining during any weight training exercise. This may cause a dangerous increase in blood pressure.