Excercises and Muscle activity - Benefits and precautions.

In addition, the well-exercised body requires a smaller amount of muscle activity for a given physical performance than the untrained body. Many studies indicate not only a lower incidence of heart attacks among the physically active than among the sedentary but also a greater likelihood, when a heart attack does occur, for the physically active per- son to recover. One possible reason is that exercise appears to promote the development of supplementary blood vessels which can take over the burden of nourishing the heart muscle when a coronary artery is blocked in a heart attack. 

In a recent study to try to explain why physical exercise may ward off heart attacks, investigators at the University of Oregon Medical School and radioactively tagged cholesterol to animals. Because of the tagging, they could follow what happened to the cholesterol. (It is a high level of blood cholesterol that is thought to foster development of atherosclerosis, the pile-up of fatty deposits on blood vessel walls that may shut down blood flow to the heart muscle, producing a heart attack.)

The Oregon workers found that the more the animals exercised, the more cholesterol was broken down; the less exercise, the higher the levels of cholesterol in the blood. In Israel recently, a special program of activity has been set up for men who have had actual heart attacks. 

In the program, exercise is gradually intensified until it becomes quite vigorous, including jogs along the Mediterranean Sea. The program is carried out under close medical super- vision. Dr. Daniel Brunner, its director and Associate Professor of Physiological Hygiene at Tel Aviv University, reports that many of the patients now are more fit than before their heart attacks-and more fit than non-trained people of their age who have not had coronary artery disease.

ACTIVITY AT ANY AGE That even elderly people, men in their 70's, can regain much of the vigor and physical function of their 40's through carefully planned physical activity has been demonstrated by a University of Southern California investigator. In the program, in which exercise is prescribed with the same care as a physician prescribes medications, 69 men aged 50 to t\7 have been working out one hour three times a week. 

Their closely supervised regimen includes calisthenics, stretching, swimming, and jog- at the end of one year, these were the results expressed in terms of: blood pressure improved by 6 percent; body fat 4.8 percent; oxygen consumption increased by 9.2 percent;  

 arm strength increased by 7.2 percent; and nervous tension reduced by 14 percent. It would be an invitation to disaster for older people and, for that matter, for younger people to rush pell-mell into vigorous activity after long years of sedentary living without having a thorough physical checkup first and without undertaking activity on a gradual, progressive basis under medical supervision. But there is growing support now for the concept that proper physical activity can help the aged and can even delay the aging process, prolonging the active years, retarding and possibly helping to avoid some degenerative diseases.