It is a daily and unfortunate scene in the family physician's office: a succession of patients for whom the best prescription is a lifestyle modification. One such modification could be an increase in physical activity. The preventive health benefits of regular physical activity are well documented.¹ Not only would physical health improve,² but the psychologic health of most patients also would improve because of the positive effects on stress-related anxiety and depression.^3,4

The obesity rate for Americans is increasing. Recent large-scale studies⁵ have estimated that between one fourth and one half of American adults are obese. The American Dietetic Association considers physical activity a vital component of weight management.⁶ McInnis⁷ and colleagues discuss the promotion of physical activity for overweight and obese patients in this issue of American Family Physician.

Despite clear benefits to many aspects of patients' health, some family physicians are reluctant to advise patients to increase their physical activity.⁸ Although regular physical activity is associated with decreased incidence of coronary heart disease, osteoporosis, stroke, colon cancer, type 2 diabetes, and obesity, the majority of American adults are irregularly active or completely sedentary.^1,9 The Centers for Disease Control and Prevention and the American College of Sports Medicine¹ recommend that adults engage in moderate-intensity activity (e.g., walking 3 to 4 mph) for at least 30 minutes per day on most—preferably all—days of the week. Epidemiologic studies indicate that American adults, particularly women, are moving away from the Healthy People 2010 objective of increasing the proportion of adults who are meeting this recommendation.¹⁰ For example, less than 15 percent of American adults engage in moderate activity for at least 30 minutes per day.¹

The U.S. Preventive Services Task Force (USPSTF) reviewed eight fair- to good-quality trials relating to physical activity and found insufficient evidence to recommend for or against behavior counseling in primary care settings to promote physical activity.¹¹ However, multicomponent interventions that combine physician advice with behavior components, such as written exercise prescriptions, individual goal setting, follow-up via telephone, mail, or Internet, and individually tailored physical activity materials and regimens, appear promising. Linking patients with community-based physical activity programs also has been shown to increase the impact of physician counseling.¹²

Healthy People 2010 guidelines differ from the USPSTF recommendations by encouraging physicians to routinely counsel their patients to be physically active (Objective 1.3a).¹⁰ However, time constraints, limited access to allied health professionals (i.e., psychologists, registered dietitians, health educators), and limited training in prescribing exercise make promoting physical activity in the primary care setting a challenge.^13,14

Throughout the past decade, randomized controlled trials such as the Activity Counseling Trial (ACT)¹⁵ and Patient-Centered Assessment Counseling for Exercise and Nutrition (PACE)¹⁶ have been used with mixed success in the primary care setting. Based on the results of the ACT, PACE, and others, the family physician can implement cost-and time-effective physical activity strategies, including the following:

• Emphasizing the link between reduced disease risk and physical activity.

• Pointing out the role of physical activity in weight control.

• Providing a written prescription for exercise.

• Emphasizing that 30 minutes of daily physical activity can make a substantial difference in long-term health outcomes.

• Encouraging patients to select activities they enjoy.

• Encouraging patients to find someone with whom to exercise.

• Encouraging patients to keep a diary to monitor their behavior.

Increasing physical activity among American adults is necessary to reduce the morbidity and mortality associated with chronic disease. Family physicians, with their characteristic emphasis on long-term care in the context of long-term relationships, are ideal agents to deliver this message. Their efforts can be bolstered by more research into which interventions are effective for increasing their patients' levels of physical activity.