Recommendations were not based on cost-effectiveness of options. Patient preferences were not discussed. Background papers providing critical appraisal of the evidence and tentative recommendations prepared by the chapter author were pre-circulated to the members. Consensus was reached on final recommendations. Benefits, Harms, and Costs Cohort studies report a consistent, strong, graded association between physical activity and incidence of CHD in men.
Insufficient evidence exists for women.
Prospective population studies and experimental studies on the secondary prevention of obesity found that increased relative risk for significant weight gain was associated with low physical activity level. Exercise alone had a significant effect on weight, but a combination of diet and exercise was most effective for preventing obesity and maintaining ideal body weight. Potential adverse effects of exercise include injury, osteoarthritis, myocardial infarction and sudden death. Few data exist on the incidence of injury during non-competitive sports. Injuries are often due to excessive levels of activity or improper techniques, and, therefore, are preventable.