title: The outcomes of a 12-week Internet intervention aimed at improving fitness and health-related quality of life in overweight adolescents: the Young & Active controlled trial.
abstract: BACKGROUND
  Overweight and obesity among adolescents may have consequences, with potentially lasting effects on health and health-related quality of life (HRQoL). Excess weight is also associated with decreases in physical activity and cardiorespiratory fitness. The aim of the current study was to investigate the short-term effects of a 12-week Internet intervention in a primary care setting intended to increase cardiorespiratory fitness and HRQoL among overweight and obese adolescents.
  
  
  METHODS
  In this controlled trial, participants (13-15 years) were non-randomly allocated to an intervention- or a control group. The intervention group received 12-weeks access to an online program providing tailored physical activity counseling based on principles from Self-determination Theory and Motivational Interviewing. The control group received standard follow-up by the school nurses. The primary outcome measure of cardiorespiratory fitness was determined using a shuttle run test. The secondary outcomes: HRQoL, leisure time exercise, body image and self-determined motivation for physical activity and exercise, were assessed by self-report measures. Age- and gender-adjusted body mass index (BMI) was calculated based on measurements of height and weight. To compare pre-to post intervention differences within groups, a paired samples t-test was used while crude differences between groups were analyzed with an independent samples t-test.
  
  
  RESULTS
  Of the 120 participants, 108 completed the study, 75 in the intervention group and 33 in the control group. Exposure to the intervention had a small effect on cardiorespiratory fitness (0.14; 95% CI [0.01;0.28]; P = 0.04), and a moderate effect on HRQoL (5.22; 95% CI [0.90; 9.53]; P = 0.02). Moreover, the control group increased significantly in BMI, yielding a moderate preventive effect on BMI (-0.39; 95% CI [-0.74;-0.03]; P = 0.03) for the intervention group.
  
  
  CONCLUSIONS
  The results suggest that the Internet intervention with tailored physical activity counseling can have beneficial short-term effect on cardiorespiratory fitness, HRQoL and BMI among adolescents with overweight and obesity.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT01700309.
authors.affiliation: Norwegian School of Sport Sciences, Oslo, Norway; Oslo and Akershus University College of Applied Sciences, Oslo, Norway.
authors.forename: Kirsti
authors.initials: K
authors.lastname: Riiser
authors.affiliation: Oslo and Akershus University College of Applied Sciences, Oslo, Norway.
authors.forename: Knut
authors.initials: K
authors.lastname: Løndal
authors.affiliation: Norwegian School of Sport Sciences, Oslo, Norway.
authors.forename: Yngvar
authors.initials: Y
authors.lastname: Ommundsen
authors.affiliation: Oslo and Akershus University College of Applied Sciences, Oslo, Norway.
authors.forename: Milada Cvancarova
authors.initials: MC
authors.lastname: Småstuen
authors.affiliation: Oslo and Akershus University College of Applied Sciences, Oslo, Norway.
authors.forename: Nina
authors.initials: N
authors.lastname: Misvær
authors.affiliation: Oslo and Akershus University College of Applied Sciences, Oslo, Norway.
authors.forename: Sølvi
authors.initials: S
authors.lastname: Helseth
mesh_terms: D000293:Adolescent; D001828:Body Image; D003376:Counseling; D015444:Exercise; D005260:Female; D006801:Humans; D020407:Internet; D008297:Male; D009042:Motivation; D062405:Motivational Interviewing; D009765:Obesity / Q000523:psychology; D050177:Overweight / Q000523:psychology; D010809:Physical Fitness; D011788:Quality of Life; D016896:Treatment Outcome