What Are the Specific Benefits of Exercise?
Longevity and Aging
Exercise, even after age 50, can add healthy and active years to one's life. Adding workouts that focus on speed and agility may be even more protective for older people. Flexibility exercises help reduce the stiffness and loss of balance that accompanies aging. Simply walking regularly can prolong life in the elderly.
Moderately fit people, even if they smoke or have high blood pressure, have a lower mortality rate than the least fit.
Studies continue to show that it is never too late to start exercising and that even small improvements in physical fitness can significantly lower the risk of death.
Resistance training is important for the elderly, because it is the only form of exercise that can slow and even reverse the decline in muscle mass, bone density, and strength.
Cardiovascular Health (Heart Disease and Stroke)
Heart Failure. In one study, patients between the ages of 61 and 91 increased their oxygen consumption by 20% after six months by engaging in supervised treadmill and stationary bicycle exercises. Performing daily hand grip exercises may improve blood flow through the arteries of patients with heart failure. Traditionally, heart failure patients have been discouraged from exercising. Now, exercise is proving to be helpful for many of these patients and, when performed under medical supervision, does not pose a risk for a heart attack.
Stroke. According to one analysis, a group of 11,000 men, men who burned between 2,000 and 3,000 calories a week (about an hour of brisk walking five days a week) cut their risk of stroke in half. The benefits of exercise on stroke are uncertain. Groups who burned between 1,000 and 2,000 calories or more than 3,000 calories per week also gained some protection against stroke but to a lesser degree. In the same study, exercise that involved recreation was more protective than exercise routines consisting simply of walking or climbing.
General Guidelines. Inactivity is one of the four major risk factors for heart disease, on par with smoking, unhealthy cholesterol, and even high blood pressure. Children should be especially encouraged to exercise every day to prevent heart disease later in life. Exercise does not increase the maximum heart rate, but a fit heart can pump more blood at this maximum level and can sustain it longer with less strain. Exercise even helps reverse some of the effects of smoking. Children should be especially encouraged to exercise every day to prevent heart disease later in life. Like all muscles, the heart becomes stronger and larger as a result of exercise so it can pump more blood through the body with every beat. For preventing heart disease frequency of exercises may be more important than duration. The resting heart rate of those who exercise is also slower, because less effort is needed to pump blood.
Effect on Coronary Artery Disease and Cholesterol Levels. People who maintain an active lifestyle have a 45% lower risk of developing coronary heart disease than do sedentary people. A recent study reported that moderate dietary changes improve cholesterol levels and so lower the risk for coronary artery disease only when an aerobic exercise program is also followed. Regular aerobic exercises -- brisk walking, jogging, swimming, biking, aerobic dance, and racquet sports -- are the best forms of exercise for lowering LDL and raising HDL cholesterol levels. It may take up to a year of sustained exercise for HDL levels to show significant improvement. Burning at least 250 calories a day (the equivalent of about 45 minutes of brisk walking or 25 minutes of jogging) seems to confer the greatest protection against coronary artery disease. Even moderate exercise, however, reduces the risk of heart attack, but in terms of raising HDL levels, more is better. Resistance (weight) training offers a complementary benefit by reducing LDL levels. Triglycerides, which rise after a high-fat meal, can be lowered either with a single, prolonged (about 90 minutes) aerobic session or by several shorter sessions during the day. One study indicates, however, that short-bursts of exercise actually increase LDL oxidation -- the process that makes LDL dangerous to the heart -- so individuals should always aim for a consistency in their exercise program. Before engaging in any strenuous exercise, it is advisable to consult a physician.
High Blood Pressure. No person with high blood pressure should start an exercise program without consulting a physician. Before exercising, people with hypertension should avoid caffeinated beverages, which increase heart rate, the workload of the heart, and blood pressure during physical activity. In one study, for example, moderate exercise (jogging two miles a day) controlled hypertension so well that more than half the patients who had been taking drugs for high blood pressure were able to discontinue their medication. Studies have shown that high-intensity exercise may not lower blood pressure as effectively as moderate intensity exercise. Sedentary people have a 35% greater risk of developing hypertension than athletes do. Studies indicate that regular exercise helps keep arteries elastic, even in older people, which in turn keeps blood flowing and blood pressure low. Studies have indicated that T'ai Chi, an ancient Chinese exercise involving slow, relaxing movements may lower blood pressure almost as well as moderate-intensity aerobic exercises.
Diabetes
Regular exercise, even of moderate intensity, improves insulin sensitivity. Aerobic exercise is proving to have significant and particular benefits for people with both type 1 and type 2 diabetes; it increases sensitivity to insulin, lowers blood pressure, improves cholesterol levels, and decreases body fat. Diabetes, particularly type 2, is reaching epidemic proportions throughout the world as more and more cultures adopt Western dietary habits. In fact, studies of older people who engage in regular, moderate, aerobic exercise (e.g., brisk walking, biking) lower their risk for diabetes even if they don't lose weight. Anyone on insulin or who has complications from diabetes must take special precautions before embarking on a workout program (see, What Are the Hazards of Exercise?, below).
Effects on Bones and Joints
Back Problems. One of the most common complaints of modern men and women, lower-back pain, afflicts up to 80% of all Americans. The best exercises for athletes with bad backs include swimming, walking, and cross-country skiing. High-impact sports, including aerobic dance and downhill skiing, should be avoided. An appropriate exercise program focusing on flexibility and strengthening the muscles in the abdomen may help prevent back problems. However, the classic full sit-up (raising your head and shoulders off the floor up to your knees) may aggravate back pain and should be avoided by anyone at risk for lower back problems. Yoga stretching is beneficial and can be incorporated into the warm-up and cool-down periods.
