title: Cumulative and bidirectional association of physical activity and sedentary behaviour with health-related quality of life in adolescents.
abstract: BACKGROUND
  The directionality of the association of physical activity (PA) and sedentary behaviour (SB) with health-related quality of life (HRQoL) remains unknown in adolescents. This study aimed to investigate the association of 2-year cumulative level of PA and SB with HRQoL and the reverse association.
  
  
  METHODS
  We included 1445 adolescents in France from a 2-year longitudinal study with three follow-up times (PRALIMAP trial). At each follow-up, adolescents completed the International Physical Activity Questionnaire for PA and SB and the Duke Health Profile for HRQoL. Statistical analyses involved linear and logistic regressions adjusted for socio-demographic characteristics.
  
  
  RESULTS
  The cumulative number of times an adolescent achieved the PA recommendations during the 2 years was associated with better physical, mental, social and general HRQoL (p for trend < 0.0001). In contrast, high SB predicted low HRQoL for most dimensions except social HRQoL (p = 0.12). Combining PA and SB, the effect of recommended PA on HRQoL was offset in part by high SB. In the reverse association, high HRQoL predicted high PA (overall, vigorous, moderate and recommended PA), but was not associated with SB.
  
  
  CONCLUSIONS
  The association between PA and HRQoL was cumulative and bidirectional among adolescents, whereas low HRQoL seemed to be a consequence of high SB rather than a cause (cumulative but not bidirectional). Promoting recommended PA and low SB may help improve HRQoL among adolescents, with a possible virtuous cycle with regard to PA.
authors.affiliation: EA 4360 APEMAC, University of Lorraine, Paris Descartes University, 54500, Nancy, France.
authors.forename: Abdou Y
authors.initials: AY
authors.lastname: Omorou
authors.affiliation: EA 4360 APEMAC, University of Lorraine, Paris Descartes University, 54500, Nancy, France.|National Conservatory of Arts and Crafts (CNAM), Paris, France.
authors.forename: Johanne
authors.initials: J
authors.lastname: Langlois
authors.affiliation: National Conservatory of Arts and Crafts (CNAM), Paris, France.
authors.forename: Edith
authors.initials: E
authors.lastname: Lecomte
authors.affiliation: EA 4360 APEMAC, University of Lorraine, Paris Descartes University, 54500, Nancy, France.
authors.forename: Serge
authors.initials: S
authors.lastname: Briançon
authors.affiliation: EA 4360 APEMAC, University of Lorraine, Paris Descartes University, 54500, Nancy, France. anne.vuillemin@univ-lorraine.fr.
authors.forename: Anne
authors.initials: A
authors.lastname: Vuillemin
mesh_terms: D000293:Adolescent; D005260:Female; D005602:France; D006304:Health Status; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D009043:Motor Activity; D011788:Quality of Life; D057185:Sedentary Behavior; D057566:Self Report
keywords: Adolescents; Health-related quality of life; Physical activity; Sedentary behaviour