title: Relationship between physical activity and general mental health.
abstract: OBJECTIVE
  We investigated the relationship between physical activity and mental health and determined the optimal amount of physical activity associated with better mental health.
  
  
  METHODS
  Self-reported data from a national random sample of 7674 adult respondents collected during the 2008 U.S. Health Information National Trends 2007 Survey (HINTS) were analyzed in 2012. Mental health was plotted against the number of hours of physical activity per week using a fractional 2-degree polynomial function. Demographic and physical health factors related to poorer mental health were examined. The optimal range of physical activity associated with poorer mental health was examined by age, gender, and physical health.
  
  
  RESULTS
  A curvilinear association was observed between physical activity and general mental health. The optimal threshold volume for mental health benefits was of 2.5 to 7.5h of weekly physical activity. The associations varied by gender, age, and physical health status. Individuals who engaged in the optimal amount of physical activity were more likely to have reported better mental health (odds ratio=1.39, p=0.006).
  
  
  CONCLUSIONS
  This study established a hyperbolic dose-response relationship between physical activity and general mental health, with an optimal range of 2.5 to 7.5h of physical activity per week.
authors.affiliation: Department of Health and Behavior Studies, Teachers College, Columbia University, New York, NY 10027, USA. kys0101@snu.ac.kr
authors.forename: Yeon Soo
authors.initials: YS
authors.lastname: Kim
authors.forename: Yoon Soo
authors.initials: YS
authors.lastname: Park
authors.forename: John P
authors.initials: JP
authors.lastname: Allegrante
authors.forename: Ray
authors.initials: R
authors.lastname: Marks
authors.forename: Haean
authors.initials: H
authors.lastname: Ok
authors.forename: Kang
authors.initials: K
authors.lastname: Ok Cho
authors.forename: Carol Ewing
authors.initials: CE
authors.lastname: Garber
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D015444:Exercise / Q000523:psychology*; D005260:Female; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D016015:Logistic Models; D008297:Male; D008603:Mental Health; D008875:Middle Aged; D012737:Sex Factors; D012959:Socioeconomic Factors; D013997:Time Factors; D014481:United States / Q000453:epidemiology