Adolescent Fitness Assessment Program

Diabetes Clinical Trial

— AFAP  

Official title:

Increasing Self-efficacy and VO2 Max Scores in Obese Adolescents: a Peer Modeling Intervention

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01382121
• Other study ID #: PeakVO2 PM RCT
• Status: Completed
• Phase: Phase 0
• First received: April 21, 2011
• Last updated: June 25, 2012
• Start date: September 2010
• Est. completion date: May 2012

Study information

• Verified date: June 2012
• Source: University of Western Ontario, Canada
• Contact: n/a
• Is FDA regulated: No
• Health authority: Canada: Ethics Review Committee
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 49
• Est. completion date: May 2012
• Est. primary completion date: April 2012
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 10 Years to 17 Years

Eligibility

Inclusion Criteria:

• Children and adolescents aged 10-17 years who are obese, defined as Body Mass Index greater than the 95th percentile for age and gender

Exclusion Criteria:

• Participants who smoke, are pregnant or have an illness or disease will be excluded from the study.

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Outcomes Assessor), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Diabetes

Intervention

Behavioral:
• Peer Modeling
Participants watch a video of an adolescent completing the fitness test and explaining coping mechanisms to preform the test well.
• Control
watching a video unrelated to the fitness test and self-efficacy

Locations

Country	Name	City	State
Canada	Exercise and Health Psychology Laboratory	London	Ontario

Sponsors (1)

Lead Sponsor	Collaborator
University of Western Ontario, Canada

Country where clinical trial is conducted

Canada, 

References & Publications (7)

Cairney J, Hay JA, Faught BE, Léger L, Mathers B. Generalized self-efficacy and performance on the 20-metre shuttle run in children. Am J Hum Biol. 2008 Mar-Apr;20(2):132-8. — View Citation

Carrel AL, Sledge JS, Ventura SJ, Clark RR, Peterson SE, Eickhoff J, Allen DB. Measuring aerobic cycling power as an assessment of childhood fitness. J Strength Cond Res. 2007 Aug;21(3):685-8. — View Citation

Greenhalgh J, Dowey AJ, Horne PJ, Fergus Lowe C, Griffiths JH, Whitaker CJ. Positive- and negative peer modelling effects on young children's consumption of novel blue foods. Appetite. 2009 Jun;52(3):646-53. doi: 10.1016/j.appet.2009.02.016. Epub 2009 Mar 6. — View Citation

Horne PJ, Hardman CA, Lowe CF, Rowlands AV. Increasing children's physical activity: a peer modelling, rewards and pedometer-based intervention. Eur J Clin Nutr. 2009 Feb;63(2):191-8. Epub 2007 Sep 19. — View Citation

Jones RA, Okely AD, Caputi P, Cliff DP. Perceived and actual competence among overweight and non-overweight children. J Sci Med Sport. 2010 Nov;13(6):589-96. doi: 10.1016/j.jsams.2010.04.002. Epub 2010 Jul 2. — View Citation

Korsten-Reck U, Kaspar T, Korsten K, Kromeyer-Hauschild K, Bös K, Berg A, Dickhuth HH. Motor abilities and aerobic fitness of obese children. Int J Sports Med. 2007 Sep;28(9):762-7. Epub 2007 May 11. — View Citation

Willms JD, Tremblay MS, Katzmarzyk PT. Geographic and demographic variation in the prevalence of overweight Canadian children. Obes Res. 2003 May;11(5):668-73. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Physiological measure: Aerobic Fitness	Changes in aerobic fitness from baseline (day 1) to follow-up (day 7) will be evaluated by a trained exercise physiologist using a standardized, maximal incremental exercise protocol (Modified Bruce protocol) on a treadmill. Expired gases will be analyzed using a metabolic cart (Cosmed Quark B2 cardiopulmonary testing, Image Monitoring). Peak oxygen consumption (Peak VO2) will be determined by taking the highest values during a 15 second period and expressed in absolute (l/min) and relative (ml/kg/min) units with the latter unit used for subsequent analysis.	Baseline (day 1) and follow-up (day 7)	No
Primary	Psychological: Self-Efficacy	Changes in self-efficacy from baseline (day 1) to follow-up (day 7) will be evaluated by an 18-item Self-Efficacy Scale (adapted from McAuley & Milhalko, 1998) to evaluate participants' confidence to successfully perform increasing intensities and durations of physical activity.	Baseline (day 1) and follow-up (day 7)	No
Secondary	Changes in variability (standard deviation)	Changes in variability (standard deviation) in the aerobic fitness and self-efficacy data will be analyzed using statistical software.	Baseline (day 1) and follow-up (day 7)	No

External Links

•   Exercise and Health Psychology Laboratory