CHAPTER 6. REGULAR EXERCISE 151 for measuring the intensity of exercise in beginners than in conditioned athletes. Most regular exercisers do not routinely measure their heart rate during their workouts, relying instead on subjective measures, such as deep breathing and sweating, to know when they are in the zone. Patients who are subject to extreme tachycardia should take their pulse while exercising To assure that exercise intensity remains at a safe level, the pulse rate should remain below 85% of the person's theoretical maximum age-adjusted heart rate(220- age) Although the evidence to date shows that exercise must be aerobic for it to be beneficial in reducing long-term risk for coronary artery disease exercise at any level above the sedentary state is helpful for weight loss and for producing the mental benefits associated with regular physical activity. An even modest level of regular exercise frequency(1 or 2 hours per week at nonaerobic intensity) probably reduces mortality. Moderate intensity physical activity other than regular leisure-time exercise, the so-called lifestyle approach, may also be beneficial for improving health and reducing mortality. Objectives for Reqular Exercise Given the known benefits of regular exercise and the harmful consequences of a sedentary lifestyle, the objectives for the activity can be set out in a straightforward manner. Regardless of the accumulated data about the long term health benefits of regular exercise, most regular exercisers engage in the activity because of the immediate benefits of feeling good and feeling better about themselves. When counseling patients about regular exercise, it is very important to bear this in mind. most regular exercisers do not engage in the activity in order to reduce their risk for future disease Risk reduction does not motivate most nonexercisers to start exercising either, unless a negative health event such as a heart attack shocks them into appropriate action,or they are exercising to promote weight loss. When patients ask about the benefits of regular exercise, the clinician should stress the short-term gains feeling good, improved personal appearance, and increased self-esteem. The clinician should point out though that most but not all sedentary people who become regular exercisers experience these gains. Long-term benefits will also motivate some patients and should be noted. Risks of reqular Exercise in the otherwise healthy Patient Regular exercise has its risks as well as its benefits. Virtually all of the risks are preventable or modifiable. The most common risk of exercise is injury. There are three types of injuries: intrinsic, extrinsic, and overuse. Intrinsic injury is that caused by the nature of the activity or sport, for example, shin splints in running. Extrinsic injury is that caused by an external factor, for example, a cyclist hit by an automobile. Overuse injury results from exercising too far