title: Associations of Health Club Membership with Physical Activity and Cardiovascular Health.
abstract: BACKGROUND
  This study evaluates whether a health club membership is associated with meeting the US physical activity (PA) guidelines and/or favorable cardiovascular health.
  
  
  METHODS
  Using cross-sectional data of health club members (n = 204) and non-members (n = 201) from April to August 2013, this is the first study to our knowledge to examine a health club membership in relation to objectively measured cardiovascular health indicators including resting blood pressure, resting heart rate, body mass index, waist circumference, and cardiorespiratory fitness based on a non-exercise test algorithm. To determine the total PA and sedentary time, this study used a comprehensive PA questionnaire about both aerobic and resistance activities at the health club, as well as lifestyle activities in other settings, which was developed based on the International Physical Activity Questionnaire (IPAQ).
  
  
  RESULTS
  The odds ratios (95% confidence interval) of meeting either the aerobic, resistance, or both aerobic and resistance PA guidelines for members compared to non-members were 16.5 (9.8-27.6), 10.1 (6.2-16.3), and 13.8 (8.5-22.4), respectively. Significant associations of health club membership with more favorable cardiovascular health outcomes and sedentary behavior were observed for resting heart rate (B: -4.8 b/min, p<0.001), cardiorespiratory fitness (B: 2.1 ml/kg/min, p<0.001), and sedentary time (B: -1.4 hours, p<0.001). Participants with a health club membership of >1 year had more favorable health outcomes, with a smaller waist circumference (men, B: -4.0 cm, p = 0.04; women, B: -3.4 cm, p = 0.06), compared to non-members.
  
  
  CONCLUSIONS
  Health club membership is associated with significantly increased aerobic and resistance physical activity levels and more favorable cardiovascular health outcomes compared to non-members. However, longitudinal, randomized controlled trials would be clearly warranted as cross-sectional data prohibits causal inferences.
authors.affiliation: Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Illinois, United States of America.
authors.forename: Elizabeth C
authors.initials: EC
authors.lastname: Schroeder
authors.affiliation: Department of Kinesiology, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Welk
authors.affiliation: Department of Kinesiology, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Warren D
authors.initials: WD
authors.lastname: Franke
authors.affiliation: Department of Kinesiology, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Duck-Chul
authors.initials: DC
authors.lastname: Lee
mesh_terms: D000328:Adult; D001794:Blood Pressure; D000072599:Cardiorespiratory Fitness; D015444:Exercise; D005260:Female; D020446:Fitness Centers / Q000706:statistics & numerical data*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011795:Surveys and Questionnaires; D014481:United States; D055105:Waist Circumference