THE BENEFITS AND RISKS OF EXERCISE TRAINING

A sedentary lifestyle is one of the 5 major risk factors (along with high blood pressure, abnormal values for blood lipids, smoking, and obesity) for cardiovascular disease (CVD). Even for heart attack patients who participate in a formal exercise program, the death rate is reduced by 20% to 25%.

 

Cardiorespiratory Fitness reduces risk of developing Hypertension, osteoporosis, depression, osteoarthritis, Metabolic syndrome, dementia and Alzheimer disease, diabetes mellitus, breast, colon and other cancers. High levels of physical activity (PA) have also been demonstrated to reduce CVD Mortality risk in high-risk populations, including those with Type 2 Diabetes and the elderly.

The Physical Activity Federal Guidelines call for a minimum of 150 minutes per week of moderate aerobic PA or 75 minutes per week of vigorous aerobic PA; the Institute of Medicine suggests 60 minutes daily of some aerobic PA. However recent evidence suggests that substantial benefits are obtained with exercise training doses much lower than these guidelines. In a recent study of 13000 runners and 42000 nonrunners followed on average for 15 years, runners had impressive reductions in CVD mortality of 45%, with an average increase in life expectancy of 3 years. Persistent runners had the greatest reduction in risk, whereas those who began running but stopped or vice versa received about half of the benefit.

 

Regarding resistance exercise training such as weight lifting improves muscular strength, helps to improve insulin insensitivity and prevent or reverse sarcopenia (a pernicious and progressive problem that commonly affects individuals as they age). Therefore, including resistance exercise training for at least 15 to 20 minutes twice weekly and including frequent repetition exercises of the large muscle groups, combined with aerobic PA, would be ideal.

 

But more does not seem to be better, as running doses of >30 miles per week or walking >46 miles per week, there seems to be substantial loss of the exercise training benefit on CVD mortality. It is a good idea to be aware of the warning signs or symptoms that may indicate a problem: chest discomfort, unusual shortness of breath, dizziness or light-headedness, and heart rhythm abnormalities. If one of these symptoms occurs, medical attention should be sought immediately. However, this risk

is extremely small among regular exercises and contrary to popular view, the majority of heart attacks (approximately 90%) occur in the resting state, not during physical activity. Exercise is therefore considered to be extremely safe but if you currently have heart disease or are over 45 years of age and have two or more risk factors you should consult your physician before starting any type of exercise.