The physical benefits of regular exercise are widely touted. Aerobic exercise wards off disease while controlling weight and boosting metabolism. Weight training adds muscle strength that is important, particularly as we age. As anyone who works out can attest, exercise is exhilarating, releasing those mood boosting neurochemicals that improve your outlook. Feel good. Look good. What more can you want, right?

Health experts at Harvard Medical School say there is another level of exercise that can help you rejuvenate mentally and physically. Progressive muscle relaxation (PMR), referred to as muscle meditation, it is a systematic process in which you relax each of your muscle groups. Although it is seeing a resurgence of interest, this technique was developed by American physician Edmund Jacobson in the early 1920s.

PMR is best performed in a quiet, secluded place. You should be comfortably seated or stretched out on a firm mattress or mat. Until you learn the routine, have a friend recite the directions or listen to them on a tape, which you can prerecord.

As you progress through the routine, tighten each muscle and maintain the contraction 20 seconds before slowly releasing it. As the muscle relaxes, concentrate on the release of tension and the sensation of relaxation. Start with your facial muscles, then work down the body.

• Forehead: Wrinkle your forehead and arch your eyebrows. Hold; then relax.

• Eyes: Close your eyes tightly. Hold; then relax.

• Nose: Wrinkle your nose and flare your nostrils. Hold; then relax.

• Tongue: Push your tongue firmly against the roof of your mouth. Hold; then relax.

• Face: Grimace. Hold; then relax.

• Jaws: Clench your jaws tightly. Hold; then relax.

• Neck: Tense your neck by pulling your chin down to your chest. Hold; then relax.

• Back: Arch your back. Hold; then relax.

• Chest: Breathe in as deeply as you can. Hold; then relax.

• Stomach: Tense your stomach muscles. Hold; then relax.

• Buttocks and thighs: Tense your buttocks and thigh muscles. Hold; then relax.

• Arms: Tense your biceps. Hold; then relax.

• Forearms and hands: Tense your arms and clench your fists. Hold; then relax.

• Calves: Press your feet down. Hold; then relax.

• Ankles and feet: Pull your toes up. Hold; then relax.

The entire routine should take 15 to 20 minutes. For maximum benefit, you should do it twice daily. In about two weeks you will begin to feel the full range of benefits which include a decrease in the anxiety that comes with stress, improved concentration, and increased spontaneity and creativity.