Adolescent Fitness Assessment Program
Condition: Diabetes
Study type: Interventional
Phase: Early Phase 1

Summary: 
      The purpose of this study is to implement a peer modeling intervention to improve
      self-efficacy and aerobic fitness in obese youth. A total of 40 obese (defined as Body Mass
      Index greater than the 95th percentile for age and gender) youth will participate in this
      study.
    

Detailed description: 
      There has been a dramatic increase in the prevalence of overweight and obese children in all
      regions of Canada. In fact, Canada has one of the highest rates of childhood obesity compared
      to other developed countries. This is disconcerting because this preventative condition is
      strongly associated with the risk of future disease, such as adult obesity, insulin
      resistance, type 2 diabetes, cardiovascular problems and psychosocial distress. This trend is
      a driving factor to develop effective strategies for assessment and intervention.

      Aerobic fitness is the ability of the cardiovascular and respiratory system to deliver oxygen
      to working muscles and utilize that oxygen to produce energy. Aerobic fitness is a strong
      indicator of physical activity and also correlates with the aforementioned diseases. It is
      measured as peak ventilatory oxygen (peak VO2; mL/kg min), and is evaluated using a maximal
      incremental exercise protocol on a treadmill, whereby expired gases are analyzed using a
      metabolic cart. Aerobic fitness values are inconsistent in youth, particularly obese youth.
      This discrepancy is due to low self-efficacy. Self-efficacy refers to the belief that one has
      the power and capabilities to produce an effect. Low self-efficacy is prominent in obese
      youth because they lack actual and perceived physical competence and social support. This may
      translate into less effort invested by this population into physical activity, and by the
      same token, aerobic fitness tests. To date, no experimental studies have attempted to address
      these psychological variables and apply an intervention to achieve accurate peak VO2 values
      in obese adolescents.

      Peer modelling is the demonstration of particular behaviors that are learned observationally
      and is a powerful source of self-efficacy. This mode of learning has been very successful in
      increasing the consumption of new foods (36 subjects) and activity levels (100 subjects) in
      children. Based on this success, it would suggest that the investigators could confidently
      apply it to this study. Therefore the main objective is to examine the effect of a modeling
      intervention (DVD film) on self-efficacy and peak VO2 in obese youth during a maximal
      treadmill test. Models will demonstrate and articulate increased confidence to perform the
      test and offer a variety of strategies to cope with the maximal effort and overcome the
      associated challenges during the test (e.g. shortness of breath, sweating, and increased
      heart rate). The models will not be participants in the study.

      Obese (defined as Body Mass Index greater than the 95th percentile for age and gender) youth
      (10-17 years, N = 40) who receive written consent from a parent or guardian will be asked to
      participate in the study. Prior to undertaking the aerobic fitness test, children are
      required to seek approval from their family physician by completing the Physical Activity
      Readiness Questionnaire (PAR-Q).

      Participants will be randomized after baseline measures are completed into one of two
      conditions: peer modeling intervention or control to ensure group equivalency. Following
      randomization, participants in the intervention group will watch the peer modeling DVD film
      in the lab. Those in the control group will view a DVD film of similar length about
      nutrition. After seven days, participants in both groups will return for follow-up. One week
      is a suitable interval because it provides time for participants to reflect on any
      information they received from the DVD films and minimize external confounding factors, while
      not providing enough time to see changes in fitness (which requires approximately 3 months).
      Prior to the second exercise test, participants will watch the DVD film they viewed the
      previous week. Afterwards, participants will complete their peak VO2 test and self-reported
      measures. All participants will be asked not to change their normal physical activity
      patterns during the week.

      To complete a peak VO2 test, participants will be required to complete a maximal incremental
      exercise protocol on a treadmill. The test will be conducted by trained personnel and
      terminated when participants are unable to continue the protocol, or when their vital signs
      warranted discontinuation.

      The results of this RCT will provide an accurate measurement of aerobic fitness, which is
      crucial to assessing health status, risk of disease and assisting in planning programs aimed
      at improving quality of life in adolescents.
    

Intervention name(s): Peer Modeling; Control
Intervention type(s): Behavioral; Behavioral
Intervention description(s): Participants watch a video of an adolescent completing the fitness test and explaining coping mechanisms to preform the test well.; watching a video unrelated to the fitness test and self-efficacy
Other intervention name(s): Observational Learning; Coping Model; Contact control; Active control
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Peer modeling; Observational learning; Obesity; Adolescents; Maximum ventilatory oxygen; Aerobic fitness; Health behaviour