Comparison of lifestyle and structured interventions to increase physical activity and cardiorespiratory fitness: a randomized trial

JAMA. 1999 Jan 27;281(4):327-34. doi: 10.1001/jama.281.4.327.


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% CI, 0.42-1.25 kcal/kg per day; P<.001) and 0.69 (95% CI, 0.25-1.12 kcal/kg day; P = .002) for activity, and 0.77 (95% CI, 0.18-1.36 mL/kg per minute; P = .01) and 1.34 (95% CI, 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% CI, -5.54 to -1.72 mm Hg; P<.001] and -3.26 [95% CI, -5.26 to -1.25 mm Hg; P = .002]) and diastolic blood pressure (-5.38 [95% CI, -6.90 to -3.86 mm Hg; P<.001] and -5.14 [95% CI, -6.73 to -3.54 mm Hg; P<.001) for the lifestyle and structured activity groups, respectively. Neither group significantly changed their weight (-0.05 [95% CI, -1.05 to 0.96 kg; P = .93] and 0.69 [95% CI, -0.37 to 1.74 kg; P = .20]), but each group significantly reduced their percentage of body fat (-2.39% [95% CI, -2.92% to -1.85%; P<.001] and -1.85% [95% CI, -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.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Blood Pressure
  • Body Composition
  • Cardiovascular Diseases / epidemiology
  • Cardiovascular Diseases / prevention & control*
  • Energy Metabolism
  • Exercise Test
  • Exercise* / physiology
  • Female
  • Health Behavior
  • Humans
  • Life Style*
  • Lipoproteins / blood
  • Male
  • Middle Aged
  • Models, Psychological
  • Oxygen Consumption
  • Risk Factors


  • Lipoproteins