title: Reflections on physical activity intervention research in young people - dos, don'ts, and critical thoughts.
abstract: BACKGROUND
  Physical activity has been associated with many benefits throughout the life course. As levels of physical activity appear to be insufficient in large populations, the development of effective interventions to promote or maintain activity levels in young people are therefore of key public health concern. Physical activity intervention research in young people is challenging, but this should not be a reason to continue conducting inferior quality evaluations. This paper highlights some of the key issues that require more careful and consistent consideration to enable future research to achieve meaningful impact.
  
  
  CONCLUSIONS
  This paper critically evaluates, amongst others, current research practice regarding intervention development, targeting, active involvement of the target population, challenge of recruitment and retention, measurement and evaluation protocols, long-term follow-up, economic evaluation, process evaluation, and publication. It argues that funders and researchers should collaborate to ensure high quality long-term evaluations are prioritised and that a trial's success should be defined by its quality, not its achieved effect. The conduct and publication of well-designed evaluations of well-defined interventions is crucial to advance the field of youth physical activity promotion and make us better understand which intervention strategies may or may not work, why, and for whom.
authors.affiliation: MRC Epidemiology Unit & UKCRC Centre for Diet and Activity Research (CEDAR), University of Cambridge School of Clinical Medicine, Box 285, Addenbrookes Hospital, Hills Road, Cambridge, CB2 0QQ, UK. esther.vansluijs@mrc-epid.cam.ac.uk.
authors.forename: Esther M F
authors.initials: EM
authors.lastname: van Sluijs
authors.affiliation: Epidemiology, Biostatistics and Prevention Institute, University of Zürich, Hirschengraben 84, CH-8001, Zürich, Switzerland. susi.kriemler@ifspm.uzh.ch.
authors.forename: Susi
authors.initials: S
authors.lastname: Kriemler
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000523:psychology*; D015444:Exercise / Q000523:psychology*; D006293:Health Promotion / Q000379:methods*; D006801:Humans; D012106:Research