6 Clinical Trials for Various Conditions
This study tests whether different physical activity patterns are linked an individual's genes.
The objective of this project is to determine the biological, neurobehavioral, and behavioral compensatory responses to exercise training-induced energy deficits in overweight to obese men and women. Participants will engage in exercise at either 2 days or 6 days per week for 12 weeks and have body composition assessed via DXA before and after the exercise intervention. Accumulated energy balance (weight loss converted to kcal) will be compared to exercise energy expenditure to determine each individual's level of compensation, termed compensation index. Predictors of compensation index that will be assessed will include hunger/satiety hormone concentrations at rest and in response to a meal, reward driven feeding, changes in metabolic rate, and energy intake throughout the intervention. Exercise reinforcement and physical activity will also be assessed as a separate aim to determine if exercise reinforcement can be increased and if this can promote greater habitual physical activity after the intervention has ceased.
Over 70% of Americans are either overweight or obese, putting them at risk for many chronic diseases including diabetes. Exercise is commonly used as a weight loss and weight loss maintenance strategy. However, exercise-induced weight loss is often much less than expected as individuals compensate for a large portion of the energy expended through exercise, resisting maintenance of the negative energy balance needed for weight loss. Our prior research, in agreement with others, point to increases in energy intake as the primary compensatory response when exercising for weight loss; however, mechanisms promoting this behavior have yet to be fully elucidated. With obesity and diabetes prevalence continually rising, innovative research is needed to identify novel mechanisms promoting energy compensation with exercise. The long-term goal of this proposal is to reduce the incidence and improve the outcomes of obesity-related diseases by developing interventions that will attenuate compensation for the energy expended through exercise and thus improve initial weight loss and weight loss maintenance. The present proposal will take the necessary first steps towards our long-term goal by identifying novel mechanisms promoting energy intake when exercising for weight loss. One's reinforcing value of food, attentional bias and inhibitory control for food cues play an important role in feeding behaviors, independent of hunger. These behaviors are largely a product of the central dopamine reward system, which is also in play with exercise behavior. This provides mechanistic support for our central hypothesis, that exercise evokes increases in food reinforcement, attentional bias, and lowers inhibitory control for food cues to promote greater energy intake in effort to maintain energy homeostasis. The rationale for this project is by elucidating the mechanisms mediating energy compensation, future interventions can be designed that attenuate this response to improve the utility of exercise as a weight loss intervention to prevent and manage T2DM. The overall objective of the current proposal is to demonstrate an acute bout of exercise alters food reinforcement, attentional bias and inhibitory control for food cues. Upon completion, we will have a greater understanding of the mechanisms underpinning compensatory increases in energy intake when exercising. These findings will pave the way for future clinical trials testing this hypothesis in the context of a long-term exercise intervention. This contribution is significant, as the identification of novel mechanisms influencing energy compensation with exercise is needed to provide strong support for the development of novel, evidence-based interventions to attenuate this compensatory response to exercise, improving its efficacy for weight control and chronic disease management.
Contingency Management (CM) is highly effective in promoting recovery from substance use disorders, but benefits tend to attenuate over time when CM is discontinued. Identifying modifications of CM delivery that can extend its benefits is an important goal. The goal of this study is to evaluate the use of reinforcements to increase physical activity, specifically walking. The study provides a standard CM intervention to promote walking for three weeks. After three weeks, a progressively increasing variable interval schedule of reinforcement will be evaluated for increasing the durability of effects of the initial CM intervention. We hypothesize that Variable Interval Prize Contingency Management will result in greater adherence to a walking goal of 10,000 steps per day at Week 15 and Week 24 compared to the Control Condition.
The purpose of this study is to develop adaptive (AI) and micro-incentive (MI) interventions and test them against static (SI) and delayed-incentive (DI) interventions in a 4-arm randomized factorial trial to increase MVPA adoption and maintenance among inactive adults. Using neighborhood walkability and socioeconomic status, participants will be recruited from four neighborhood types: "high walkable/high SES," "high walkable/low SES," "low walkable/high SES," and "low walkable/low SES." We will evaluate synergistic or antagonistic effects of interventions and neighborhood factors on MVPA adoption by 12 months and maintenance by 24 months.
The purpose of this study is to develop and evaluate an adaptive shaping intervention based on Behavioral Economics and Operant principles to promote physical activity behaviors (adaptive group) and compare to a static physical activity intervention (static group) using a two-group randomized controlled trial design. Participants will include 20 overweight men and women (BMI 25-35 kg/m2) between 18 to 55 years. Both groups will receive the following components: 1) a pedometer, 2) self-monitoring of physical activity, 3) brief educational materials, 4) motivational prompts, 5) physical activity goals, and 6) small financial incentives. The Adaptive Intervention (AI) group will receive adaptive goals and feedback based on percentiles and a "moving" window of their recent physical activity, with incentives linked to goal attainment. Comparison intervention participants will receive the static 10,000 steps per day goal, with matching incentive amounts but without incentives linked to goal attainment. The study will compare differences in goal setting and shaping procedures that aim to increase physical activity behavior. Primary aims include: 1. To determine whether physical activity (pedometer-measured steps/day) in both the Adaptive and Static interventions increased compared to their respective baselines. Hypothesis: Both the adaptive and static interventions will result in increased physical activity over 6 months. 2. To evaluate whether the Adaptive Intervention results in greater change in physical activity (pedometer-measured steps/day) compared to the Static Intervention. Hypothesis: The adaptive intervention will result in significantly greater physical activity, measured by pedometer, compared to the static intervention over 6 months. 3. To assess participants' satisfaction with the overall program. Hypothesis: Adaptive Intervention participants will report greater overall satisfaction with the intervention than the Static Intervention participants.