Study protocol for the Exercising Together© trial : A randomized, controlled trial of partnered exercise for couples coping with cancer

Background
Most cancer survivors are married, and cancer strains the physical and mental health of each partner and their intimate relationship. We created a partnered strength training program, Exercising Together©, where the survivor and his/her partner exercise as a team in order to improve physical and mental health of both members of the couple as well as the quality of their relationship. We have not yet determined if Exercising Together© is similarly effective in couples coping with different types of cancer nor if training as a team has unique and added benefits over those derived from supervised group training and/or shared behavior change. The purpose of this study is to determine the unique benefits of Exercising Together© on physical, mental, and relational health in couples coping with breast, prostate, or colorectal cancer.

Methods
Survivors of prostate, breast and colorectal cancer (N = 294, 98 per cancer site) and their intimate, co-residing partners are recruited to participate in a single-blind, parallel group, randomized trial comparing three exercise groups that train twice per week for 6 months. Couples are randomized to one of three groups: (1) Exercising Together© where partners train as a team in a supervised group setting; (2) separate supervised group exercise classes for survivors or partners, respectively; (3) unsupervised home exercise program provided to each partner. The primary outcome is relationship quality (dyadic coping by the Dyadic Coping scale, emotional intimacy by the Dyadic Adjustment Scale, physical intimacy by the Physical Intimacy Behavior Scale, and symptom incongruence). Secondary outcomes are physical health (% body fat by DXA, serum fasting lipids (triglycerides, HDL, and LDL cholesterol), insulin resistance (HOMA-IR), resting blood pressure, C-reactive protein, TNF alpha, and physical functioning by the short Physical Performance Battery and SF-36) and mental health (depressive symptoms, anxiety, fear of recurrence) of each partner. Outcomes are collected at baseline, mid (3 months), post-intervention (6 months), and follow-up (12 months).

Discussion
Exercising Together© could shift the paradigm of survivorship care toward novel couple-based approaches that could optimize outcomes for each partner because their health is interdependent on each other and their relationship.