Abstract des Autors

Context: Even though the strong association between physical inactivity and ill health is well documented, 60% of the population is inadequately active or completely inactive. Traditional methods of prescribing exercise have not proven effective for increasing and maintaining a program of regular physical activity. Objective: To compare the 24-month intervention effects of a lifestyle physical activity program with traditional structured exercise on improving physical activity, cardiorespiratory fitness, and cardiovascular disease risk factors. Design: Randomized clinical trial conducted from August 1, 1993, through July 31, 1997. Participants: Sedentary men (n=116) and women (n=119) with self-reported physical activity of less than 36 and 34 kcal/kg per day, respectively. Interventions: Six months of intensive and 18 months of maintenance intervention on either a lifestyle physical activity or a traditional structured exercise program. Main Outcome Measures: Primary outcomes were physical activity assessed by the 7-Day Physical Activity Recall and peak oxygen consumption (VO2peak) by a maximal exercise treadmill test. Secondary outcomes were plasma lipid and lipoprotein cholesterol concentrations, blood pressure, and body composition. All measures were obtained at baseline and at 6 and 24 months. Results: Both the lifestyle and structured activity groups had significant and comparable improvements in physical activity and cardiorespiratory fitness from baseline to 24 months. Adjusted mean changes (95% confidence intervals (CIs)) were 0.84 (95% Cl, 0.42-1.25 kcal/kg per day; P<.001) and 0.69 (95% Cl, 0.25-1.12 kcal/kg day; P=.002) for activity, and 0.77 (95% Cl, 0.18-1.36 mL/kg per minute; P=.01) and 1.34 (95% Cl, 0.72-1.96 mL/kg per minute; P<.001) for VO2peak for the lifestyle and structured activity groups, respectively. There were significant and comparable reductions in systolic blood pressure (-3.63 (95% Cl, -5.54 to -1.72 mmHg; P<.001) and -3.26 (95% Cl, -5.26 to -1.25 mmHg; P=.002)) and diastolic blood pressure (-5.38 (95% Cl, -6.90 to -3.86 mmHg; P<001) and -5.14 (95% Cl, -6.73 to -3.54 mmHg; P<.001) for the lifestyle and structured activity groups, respectively. Neither group significantly changed their weight (-0.05 (95% Cl, -1.05 to 0.96 kg; P=.93) and 0.69 (95% Cl, -0.37 to 1.74 kg; P=.20)), but each group significantly reduced their percentage of body fat (-2.39% (95% Cl, -2.92% to -1.85%; P<.001) and -1.85% (95% Cl, -2.41% to -1.28%; P<.001)) in the lifestyle and structured activity groups, respectively. Conclusions: In previously sedentary healthy adults, a lifestyle physical activity intervention is as effective as a structured exercise program in improving physical activity, cardiorespiratory fitness, and blood pressure. Verf.-Referat