Exercise

Description

Exercise's Effects on Other Conditions

Physical activity contributes to health by reducing the heart rate, decreasing the risk for cardiovascular disease, and reducing the amount of bone loss that is associated with age and osteoporosis. Physical activity also helps the body use calories more efficiently, thereby helping in weight loss and maintenance. It can also increase basal metabolic rate, reduces appetite, and helps in the reduction of body fat.

Effect of Exercise on Cancer

A number of studies have indicated that regular, even moderate, exercise may reduce the risk of colon cancer and, in fact, any cancer related to obesity. A number of studies have also suggested that regular exercise, particularly if it is vigorous, reduces risks against breast cancer in women and prostate cancer in men. Indeed, a 2004 study showed that prostate cancer cells have a 27% reduction in growth when exposed to exercise serum (blood serum taken from patients who exercise) compared to control serum, suggesting that exercise changes blood chemicals to be less hospitable to cancer cells.

Several studies are underway to measure the effect of exercise on patients who have been diagnosed with cancer. Even though preliminary, they already suggest that exercise has a positive physical, mental, and emotional effect. Exercise can improve physical strength, functional capacity, and the ability to battle the negative side effects of chemotherapy, including nausea and fatigue. More studies are warranted.

Effects on the Gastrointestinal Tract

Endurance athletes often report gastrointestinal distress, such as bloating, diarrhea, and gas, even at rest. Experts suggest, however, that moderate regular exercise, might reduce the risk for some intestinal disorders, including ulcers, irritable bowel syndrome, indigestion, and diverticulosis. For example, in one 2000 study, exercise was associated with a lower risk for ulcers in men (although not in women.) Older people who exercise moderately may have a lower risk for severe gastrointestinal bleeding.

Effects on Neurologic Diseases and Mental Decline

A 2001 study reported that older people who regularly exercised had lower rates of mental deterioration, Alzheimer's, and dementia of any type. Aerobic exercise is linked with improved mental vigor, in all people, including reaction time, acuity, and math skills. Exercising may even enhance creativity and imagination. According to one study, older people who are physically fit respond to mental challenges just as quickly as unfit young adults. Another study found that walking regularly protects women from mental decline, and in fact, the more they walked per week, the more protection they enjoyed. (Stretching and weight training appear to have no such effects.) A 2004 study showed that exercise can reverse a high-fat diets harmful effects on neurologic function.

People with existing neurologic diseases, such as multiple sclerosis, Parkinsons disease, and Alzheimers disease, should be encouraged to exercise. Specialized exercise programs that improve mobility are particularly valuable for Parkinson's patients. Patients with neurological disorders who exercise experience less spasticity as well as reduction in, and even reversal of, muscle atrophy. In addition, the psychological benefits of exercise are extremely important in managing these disorders. Exercise machines, aquatic exercises, and walking are particularly useful.

Effects on Emotional Disorders

Some research has suggested that exercise may have antidepressant effects. Although there is little strong evidence that exercise can help manage depression, a number of studies have suggested benefits. The following are some examples:

• In a 2000 study 30 minutes of brisk exercise three times a week was as effective as medication in relieving the symptoms and reducing relapse in many patients with mild to mild to moderate depression.
• A 2002 study reported that over half of older women with depression that did not respond to medication improved with 10 weeks of exercise. (About a third of women who did not exercise also improved during that time.)
• Studies on elderly, depressed patients report some modest but still significant benefits from exercise, including in patient who do not response to antidepressants. (Simply participating in a group activity may help improve mood.)
• One study found that teenagers who were active in sports have a greater sense of well being than their sedentary peers; the more vigorously they exercised, the better their emotional health.
• A 2003 study found that physical inactivity is strongly linked to depression in children 8 to 12 years of age.

Specific exercises may be particularly beneficial:

Aerobics. Either brief periods of intense training or prolonged aerobic workouts can raise chemicals in the brain, such as endorphins, adrenaline, serotonin, and dopamine, that produce the so-called runners high. And, of course, weight loss and increased muscle tone can boost self-esteem.

Yoga. Yoga practice, which involves rhythmic stretching movements and breathing have been found to positively affect mood and may have clinical potential as a technique for improving and stabilizing mood. One study, in fact, suggested that men actually may have better results with yoga than with aerobic exercise. In the study men experienced significantly lower levels of tension, fatigue, and anger after yoga than after swimming. (Yoga and swimming tended to produce equal benefits in women.)

Click the icon to see an image of the benefits of yoga.

Effect of Exercise on Pregnancy

Moderate exercise in healthy pregnant women does not increase the risk for miscarriage, preterm labor, or rupture of the membrane. Not exercising, in fact, increases the risk for complications, including low-birth weight babies. Exercising increases the fetal heart rate, which in turn protects the baby.

Healthy women with normal pregnancies should exercise at least three times a week, being careful to warm up, cool down, and drink plenty of liquids. Many prenatal calisthenics programs are available.

The following are specific exercises that may benefit the pregnant woman:

• Swimming and water aerobics may be the best option for most pregnant women. Swimming has special benefits for those with fluid buildup. Water exercises involve no impact, overheating is unlikely, and swimming face down promotes optimum blood flow to the uterus.
• Performing yoga exercises under the guidance of informed instructors can be very helpful.
• Walking is also highly beneficial.

To strengthen pelvic muscles, women should perform Kegel exercises at least six times a day. This involves contracting the muscles around the vagina and urethra for three seconds 12 to 15 times in a row.

Experts generally recommend the following precautions for pregnant women who exercise:

• Fit women who have exercised regularly before pregnancy may work out intensely as long as the physician approves and no discomfort occurs.
• As a rule, for previously sedentary low-risk expectant mothers, the pulse rate should not exceed 70% to 75% of the maximum heart rate or more than 150 beats per minute. (In one study, such women exercised to 150 to 156 beats per minute three times a week without any harmful effects, but any woman should check with their physician before embarking on such a program.)
• According to one study, vigorous exercise may improve the chances for a timely delivery. All pregnant women, however, should avoid high-impact, jerky, and jarring exercises, such as aerobic dancing, which can weaken the pelvic floor muscles that support the uterus.
• During exercise, women should monitor their temperature to avoid overheating, a side effect that can damage the fetus. (Pregnant women should not use hot tubs or steam baths, which can cause fetal damage and miscarriage.)

Note: Strenuous exercise may affect the flavor of breast milk for a short time afterward. Nursing mothers who engage in such activity might want to wait about an hour after exercising before they feed their infant.