Rationale and design of REWARD (revving-up exercise for sustained weight loss by altering neurological reward and drive): A randomized trial in obese endometrial cancer survivors

Background Obesity is a leading risk factor for endometrial cancer (EC), particularly Type I forms, which are increasing in the U.S. Although death rates from most cancers have been decreasing, overall mortality in EC is increasing in the U.S. EC survivors' poor fitness combined with their surgical treatments may make weight loss particularly challenging. High intensity exercise increases neurotrophins and neurological reward via altered striatal dopamine in animals, and, in humans, chronic high intensity exercise enhances meal-induced satiety and may reduce hedonic eating. “Assisted” exercise, a mode of exercise whereby a patient's voluntary exercise rate is augmented mechanically, may modulate brain dopamine levels in Parkinson's Disease patients but has not been previously evaluated as a treatment for obesity. Methods We describe the rationale and design of the REWARD trial, which has the overarching goal of randomizing 120 obese EC survivors to “assisted” or voluntary rate cycling to evaluate the efficacy of “assisted” exercise in enhancing and sustaining weight loss. Patients in both arms will receive 3days/week of supervised exercise and 1day/week of a group dietary behavioral intervention for 16weeks and, then, will be followed for 6months. Outcomes The primary outcome is weight loss. Secondary outcomes include measures for body composition, fitness, eating behavior, exercise motivation and, quality of life as well as cognition and food reward and motivation as assessed by functional magnetic resonance imaging (fMRI) tasks. Conclusions If successful, the REWARD program could be extended to help sustain weight loss in obese cancer and non-cancer patients.