Financial Incentives to Exercise for Adolescents

Study participants in the intervention arm of the study will be asked to exercise on 3 days per week for 48 weeks. Clinical and physical assessments will be performed at baseline and after 16, 32 and 48 weeks. Participants will be randomized into one of two groups. Each group will receive payment for exercise sessions completed but one group will be on a fixed schedule of compensation and the other will have a schedule that incentivizes frequency or duration of exercise. In addition, two reference groups of age-matched participants who are normal weight and subclassified as having either low or high levels of physical activity and fitness will be tested. The reference groups will complete baseline tests and will not enter the exercise intervention program.

Inclusion criteria

for exercise intervention cohort:

• 11.0-20.9 years old
• overweight or obese
• family history of diabetes (primary or secondary relative)
• not in sports or exercise program (3 or fewer days per week of moderate-to-vigorous intensity physical activity, MVPA) for prior 3 months
• Tanner stage 2 or above

Inclusion criteria

for reference group cohort:

• 11.0-20.9 years old
• normal weight
• For low physical activity subgroup: not in sports or exercise program (3 or fewer days per week of MVPA) for prior 3 months
• For high physical activity subgroup: >30 minutes of structured MVPA on >3 days/week over the preceding 3 months
• Tanner stage 2 or above

Exclusion criteria

for all participants:

• metabolic, endocrine, cardiovascular, kidney disease
• orthopedic problems that limit physical activity
• medications or treatments that would interfere with the outcomes and interpretations
• smoking or tobacco use
• alcohol or illicit drug use
• pregnancy