Isometric exercises by definition are those in which a force is applied to a resistant object. They have a part to play in a number of programs for muscle strengthening.

A typical example is pushing against a brick wall. 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 6 to 8 seconds. The exercise should then be repeated 5 to 10 times, each time ensuring maximum muscular contraction.

A number of important points regarding isometric exercise need to be emphasized:

1. 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.

2. Isometric exercises on their own are not recommended for strength training. They must only form part of a complete exercise program.

3. 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.

� HealthChat 2000.

Dr. Sims is the Medical Director of FitStop, the UK's foremost group of health and fitness centers, and an expert on matters relating to fitness of body and mind. Having trained as a GP, he now works full-time in health promotion and has written extensively on the subject, including a monthly medical column in Mensa magazine with the TV psychiatrist, Dr Raj Persaud. Dr. Sims was the original Virgin.Net online doctor.

Article courtesy of MediaPeak