Isometric exercises are those in which a force is applied to a resistant object. A typical example is pushing against a brick wall. (See Wall Push Up)
Although there is a build up of tension in the muscles there is no actual movement. To increase strength it is necessary to maintain a position in any one exercise for between six to eight seconds. The exercise should then be repeated five to ten times, each time ensuring maximum muscular contraction.
A number of important points regarding isometric exercise need to be emphasized:
- Any one isometric exercise will only increase muscle strength at one joint angle. To strengthen the other joint positions requires repetition of further corresponding exercises.
- Isometric exercises on their own are not recommended for strength training. They must only form part of a complete exercise program.
- If you suffer from heart disease or raised blood pressure you should stay clear of isometric training. During muscular contractions in this form of exercise, blood pressure can rise quite profoundly.