OBJECTIVE To study the effects of regular walking during a golf game on various health and fitness indicators in middle-aged men. METHODS Study subjects were 55 healthy male golfers aged 48 to 64 years who had been sedentary during the 7 months before the study, and 55 age-matched, similarly sedentary controls. During the 20-week study, those in the intervention group were encouraged to play golf two to three times a week; the controls were not. Measurements of body composition, cardiorespiratory performance, motor and musculoskeletal fitness, blood pressure, and serum lipid, glucose, and insulin levels were obtained at baseline and after the 20-week study. RESULTS Walking during a golf game was a practical and safe form of physical activity with high adherence. It significantly increased aerobic performance and trunk muscle endurance, with a net difference (pretraining to posttraining change between the golfers and controls) of 36 seconds (95% confidence interval [CI]: 19 to 53 seconds, P < 0.001) for treadmill walking time and 13 seconds (95% CI: 2 to 24 seconds, P = 0.02) for static back extension. In addition, regular walking favorably affected body composition, including reductions in weight of 1.4 kg (95% CI: 0.6 to 2.1 kg, P < 0.001), in waist circumference of 2.2 cm (95% CI: 1.0 to 3.3 cm, P < 0.001), and in abdominal skin fold thickness of 2.2 cm (95% CI: 0.9 to 3.4 cm, P = 0.001). Golfers also had significantly greater increases in serum high-density lipoprotein (HDL) cholesterol levels and in the ratio of HDL cholesterol to total cholesterol. CONCLUSIONS Regular walking had many positive effects on the health and fitness of sedentary middle-aged men. Walking during a golf game is characterized by high adherence and low risk of injury and is therefore a good form of health-enhancing physical activity.