Understanding Mechanisms of Exercise Behavior Change

Study Overview
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Brief Summary
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This research seeks to examine psychological factors that may impact relationship between incentives and health behavior engagement, specifically physical activity. Additionally, it will compare the impact of two different incentive schedules on behavior engagement, one providing immediate rewards (i.e. rewards received on a daily basis) and another providing delayed rewards (i.e. rewards received at the end of the study period), with an active self-monitoring intervention condition in which no rewards are offered. Study participants will provide reports of their physical activity each day for three weeks, and in the two incentive conditions, they will receive small monetary rewards for their physical activity. Following the three week reporting and reward period, participants will complete two additional assessments, measuring psychological constructs and behavior engagement following the cessation of rewards. The study will also examine how cognitive and anthropomorphic factors may contribute to intervention response and the effects on psychological constructs.

Official Title
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Understanding Mechanisms of Exercise Behavior Change

Conditions
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Overweight and Obesity, Physical Activity, Incentives

Intervention / Treatment
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* Behavioral: self-monitoring
* Behavioral: daily incentives
* Behavioral: delayed lump sum incentives


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Complete less than 150 minutes of moderate-vigorous physical activity weekly Daily access to the internet for 3 weeks following baseline research visit Have or are willing to create an account on PayPal Willing to wear a heart rate monitor watch during physical activity for 3 weeks BMI greater than or equal to 25, from self-reported height and weight Exclusion Criteria: Diagnosis of cardiovascular, metabolic, or renal disease

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Self-Monitoring<br>Participants self-monitor their physical activity | Behavioral: self-monitoring<br>* self-monitoring of physical activity<br>|
| Experimental: Daily Incentives<br>daily payments for physical activity | Behavioral: self-monitoring<br>* self-monitoring of physical activity<br>Behavioral: daily incentives<br>* daily incentive payments for physical activity<br>|
| Experimental: Delayed Lump Sum Incentives<br>lump sum payments for physical activity | Behavioral: self-monitoring<br>* self-monitoring of physical activity<br>Behavioral: delayed lump sum incentives<br>* delayed lump sum payments for physical activity<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Moderate-vigorous physical activity minutes | summed minutes of weekly moderate intensity physical activity & vigorous intensity physical activity | Week 3 | 
| Self-Efficacy for physical activity | 8-item self-report scale measuring self-efficacy (Social Cognitive Theory, Bandura, 1977; also called perceived behavioral control, Theory of Planned Behavior, Ajzen, 1985); scores are a mean of 8 items, scored 1-7 with higher scores indicative of greater self-efficacy | Week 3 | 
| Moderate-vigorous physical activity minutes | summed minutes of weekly moderate intensity physical activity & vigorous intensity physical activity | Week 5 | 
| Self-Efficacy for physical activity | 8-item self-report scale measuring self-efficacy (Social Cognitive Theory, Bandura, 1977; also called perceived behavioral control, Theory of Planned Behavior, Ajzen, 1985); scores are a mean of 8 items, scored 1-7 with higher scores indicative of greater self-efficacy | Week 5 | 
| Attitudes toward physical activity | 12-item self-report scale (Theory of Planned Behavior, Ajzen, 1985); scores are a mean of 12 items scored from -5 to +5, with higher scores indicative of more positive attitudes | Week 3 | 
| Attitudes toward physical activity | 12-item self-report scale (Theory of Planned Behavior, Ajzen, 1985); scores are a mean of 12 items scored from -5 to +5, with higher scores indicative of more positive attitudes | Week 5 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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overweight, obesity, physical activity, exercise