title: Weekly sport practice and adolescent well-being.
abstract: OBJECTIVE
  Sport practice is widely encouraged, both in guidelines and in clinical practice, because of its broad range of positive effects on health. However, very limited evidence directly supports this statement among adolescents and the sport duration that we should recommend remains unknown. We aimed to determine sport durations that were associated with poor well-being.
  
  
  METHODS
  We conducted a survey including 1245 adolescents (16-20 years) from the general Swiss population. Participants were recruited from various settings (sport centres, peers of sport practicing adolescents, websites) and asked to complete a web-based questionnaire. Weekly sport practice was categorised into four groups: low (0-3.5 h), average (≈ recommended 7 h (3.6-10.5)), high (≈14 h (10.6-17.5)) and very high (>17.5 h). We assessed well-being using the WHO-5 Well-Being Index.
  
  
  RESULTS
  Compared with adolescents in the average group, those in the very high group had a higher risk of poor well-being (OR 2.29 (95% CI 1.11 to 4.72)), as did those in the low group (OR 2.33 (1.58 to 3.44)). In contrast, those in the high group had a lower risk of poor well-being than those in the average group (OR 0.46 (0.23 to 0.93)).
  
  
  CONCLUSIONS
  We found an inverted, U-shaped relationship between weekly sport practice duration and well-being among adolescents. The peak scores of well-being were around 14 h per week of sport practice, corresponding to twice the recommended 7 h. Practicing higher sport durations was an independent risk factor of poor well-being.
authors.affiliation: Institute of Social and Preventive Medicine, University of Lausanne, , Lausanne, Switzerland.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Merglen
authors.forename: Aline
authors.initials: A
authors.lastname: Flatz
authors.forename: Richard E
authors.initials: RE
authors.lastname: Bélanger
authors.forename: Pierre-André
authors.initials: PA
authors.lastname: Michaud
authors.forename: Joan-Carles
authors.initials: JC
authors.lastname: Suris
mesh_terms: D000293:Adolescent; D003625:Data Collection; D015444:Exercise / Q000502:physiology*; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D013177:Sports / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: adolescent; mental health; overtraining; sport; well-being