Exercise and Heart Disease

Not only does physical exercise help prevent heart disease by increasing your heart's working capacity and lowering your blood pressure, it also helps prevent weight-gain - a major risk factor for cardiovascular problems.

But that's not all: researchers from Duke University report that, even when not enough to cause weight-loss, moderate exercise produces favourable changes in blood lipid profiles - raising your levels of good cholesterol (HDL) and lowering your bad cholesterol (LDL). These changes also reduce the risk of developing a heart condition.

The best exercises to strengthen your heart are aerobic activities like brisk walking, jogging, cycling and swimming. These should be enjoyed a minimum of three times a week, for at least 30 minutes duration. However, even lighter physical activities contribute towards heart health.

The Heart and Stroke Foundation of Canada recommends the following ways to increase your daily activity level:

• Take the stairs instead of the elevator.
• Walk or ride your bike instead of taking the car.
• Get off the bus a few blocks early and walk the rest of the way.
• Cut the grass or rake the leaves.
• Go dancing.
• Go for a walk.

If you simply don't have the time to spend on a 30-minute workout, take heart. Doctors say that spreading your activity throughout the day (three separate ten-minute brisk walks, for example), will provide similar benefits in the long run.

Important Note: Talk with your doctor before you begin an exercise program or before increasing your level of physical activity if you have survived a heart attack or stroke or have other heart conditions.

Exercise and Osteoporosis

Exercise is very important for helping prevent or slowing the progression of osteoporosis (brittle bone disease). Bone mass increases significantly during puberty and reaches its peak between the ages of 20 and 30. After this age, minerals begin to leach from the bones, unless encourages to stay by the impact of exercise.

The best exercise for adding or maintaining bone mass is weight bearing (resistance) exercise. The tension applied to the muscles and bones encourages the body to compensate by increasing bone density. Since pre and post-menopausal women are at greatest risk for developing osteoporosis, it is important to perform weight-bearing exercise throughout these years. Weight bearing exercises include walking, running, hiking, low-impact aerobics, step-aerobics, cycling and weight training. (Unlike the other activities mentioned, weight training also helps build upper body bone strength.)

Exercise and Cancer

Colon Cancer: A number of studies have indicated that moderate exercise, when undertaken regularly, reduces the risk of colon cancer. Adding fuel to the fire that lack of physical activity somehow contributes to colon cancer is a new study¹ that concludes regular moderate exercise cuts the recurrence of colon cancer by half.

While no one can draw a direct link between colon cancer and the lack of exercise, a brisk half hour walk every day may well cut your personal risk of developing this life-threatening condition.

The risk for breast cancer also appears to be impacted by physical activity.

Breast Cancer: Several studies have strongly linked exercise with reducing the risk of developing breast cancer. Other studies indicate that exercise can also help prevent a recurrence of the disease.

 It appears that exercise helps reduce these risks by reducing the amount of estrogen and insulin circulating within the body. Both these hormones can promote the growth of cancers.

Although studies indicate that the greatest protection is derived by women who have exercised all their lives, increasing physical activity at any stage of life is believed to cut breast cancer risk by close to 20 percent² no matter what your individual risk factors are.

A sedentary lifestyle also contributes to weight gain, and overweight women are at greater risk of developing breast cancer because fat cells produce estrogen.

Thirty minutes of aerobic activity, five or more times a week, appears to be an effective amount of exercise to reduce breast cancer risk.

Exercise and Diabetes

Exercise can help prevent the serious complications that may accompany diabetes. If you have diabetes, your body is unable to properly produce or use insulin - the hormone that processes sugars in the foods you eat, and turns them into energy within the cells. If your body cannot process sugars properly, your cells will be starved for energy and you will build up glucose in your blood ("high blood sugar"). Over time these high glucose levels can damage major organs like your heart, eyes, and kidneys.

Regular exercise, even of moderate intensity, improves the body's sensitivity to insulin. A single session of moderate intensity exercise can increase glucose uptake by at least 40 percent.³

Since regular exercise can lower blood glucose, it may possibly reduce the amount of medication you need to control your diabetes, or even eliminate the need for medication - something you should discuss with your doctor. Regular, enjoyable exercise also helps reduce stress, which can raise your blood glucose levels.

Exercise and Depression

Feeling low? Take a walk. While this advice may seem over-simplified, exercise helps elevate the mood and can form an important strategy in controlling mild to moderate depression.

A brisk walk (or other form of exercise) causes the brain's serotonin levels to increase. Since lower levels of serotonin are linked to depression, researchers believe that higher serotonin levels are responsible for this improvement in mood.

Researchers have found that people with depression who walked, ran or performed strength training three times a week for 20 to 60 minutes duration were significantly less depressed after five weeks. When workouts continued, the improvements in mood were still demonstrable one year later.⁴

Another way in which exercise may elevate mood and reduce anxiety levels is by encouraging sleep. Getting enough sleep is important for well being and the lack of it is closely associated with depressive episodes.

Exercise can add healthy and active years to your life. Studies continue to show that it is never too late to start exercising and that even small increases in physical fitness can significantly impact your health. Go for it!

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1 Study results presented at the annual meeting of the American Society of Clinical Oncology.

2 McTiernan, A. Physical Activity and the Prevention of Breast Cancer. MedGenMed. 2(4), 2000.

3 Perseghin, G, Price, T.B., Peterson, K.F., Roden, M., Cline, G.W., Gerrow, K., Rothman, D.L., Shulman, G.I. Increased glucose transport-phosphorylation and muscle glycogen synthesis after exercise training in insulin-resistance subjects. N. Engl. J. Med. 335:1357-1362,1996.

4 Tkachuk, G.A., Martin, G.I., Exercise Therapy for Patients with Psychiatric Disorders: Research and Clinical Implications, University of Manitoba, Professional Psychology: Research and Practice, Vol. 30, No. 3.