This is an excerpt from Exercise Prescription-2nd Edition by David Swain & Brian Leutholtz.
Renowned exercise physiologist Per-Olaf Åstrand has often said that exercising is safer than remaining sedentary. This is almost universally true, because exercise produces many healthful benefits that reduce the risk of diseases associated with inactivity - coronary heart disease, cerebrovascular disease, type 2 diabetes, osteoporosis, certain forms of cancer, and so on. Yet exercise carries some risk. It increases metabolic demands on the heart and increases sympathetic nervous activity - factors that could trigger a heart attack in people who already have coronary heart disease. Because the many people with undiagnosed heart disease are particularly at risk, screening clients is critical to ensure safety. Before performing exercise testing on clients, and enrolling them in an exercise program, you should evaluate them to determine their level of risk and to decide if it is reasonably safe to proceed.
Table 1.1 provides a screening form for evaluating clients regarding their level of risk to exercise.