title: Isolated aerobic exercise and weight loss: a systematic review and meta-analysis of randomized controlled trials.
abstract: BACKGROUND
  Aerobic exercise is a common nonpharmacological intervention for the management of obesity. However, the efficacy of isolated aerobic exercise at promoting weight loss is unclear. We conducted a systematic review and meta-analysis to evaluate the efficacy of isolated aerobic exercise programs in overweight and obese populations.
  
  
  METHODS
  We searched for published randomized controlled trial reports of aerobic exercise through January 20, 2010. Trials with an isolated aerobic exercise intervention were included. A random-effect model was used to synthesize the results of each intervention.
  
  
  RESULTS
  We identified 14 trials involving 1847 patients. The duration of aerobic exercise programs ranged from 12 weeks to 12 months. Results were pooled for programs with 6-month duration and programs with 12-month duration. Six-month programs were associated with a modest reduction in weight (weighted mean difference [WMD]=-1.6 kg; 95% confidence interval [CI], -1.64 to -1.56) and waist circumference (WMD=-2.12 cm; 95% CI, -2.81 to -1.44). Twelve-month programs also were associated with modest reductions in weight (WMD=-1.7 kg; 95% CI, -2.29 to -1.11) and waist circumference (WMD=-1.95 cm; 95% CI, -3.62 to -0.29).
  
  
  CONCLUSIONS
  Moderate-intensity aerobic exercise programs of 6-12 months induce a modest reduction in weight and waist circumference in overweight and obese populations. Our results show that isolated aerobic exercise is not an effective weight loss therapy in these patients. Isolated aerobic exercise provides modest benefits to blood pressure and lipid levels and may still be an effective weight loss therapy in conjunction with diets.
authors.affiliation: Divisions of Cardiology and Clinical Epidemiology, Jewish General Hospital/McGill University, Montreal, Quebec, Canada.
authors.forename: Adrian
authors.initials: A
authors.lastname: Thorogood
authors.forename: Salvatore
authors.initials: S
authors.lastname: Mottillo
authors.forename: Avi
authors.initials: A
authors.lastname: Shimony
authors.forename: Kristian B
authors.initials: KB
authors.lastname: Filion
authors.forename: Lawrence
authors.initials: L
authors.lastname: Joseph
authors.forename: Jacques
authors.initials: J
authors.lastname: Genest
authors.forename: Louise
authors.initials: L
authors.lastname: Pilote
authors.forename: Paul
authors.initials: P
authors.lastname: Poirier
authors.forename: Ernesto L
authors.initials: EL
authors.lastname: Schiffrin
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Eisenberg
mesh_terms: D015982:Bias; D001794:Blood Pressure; D015444:Exercise; D006801:Humans; D050356:Lipid Metabolism; D009765:Obesity / Q000628:therapy; D050177:Overweight / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D016032:Randomized Controlled Trials as Topic; D013997:Time Factors; D055105:Waist Circumference; D015431:Weight Loss