Protein Supplementation and Resistance Training in Childhood Cancer Survivors.

PURPOSE: Muscle weakness, low lean body mass, and poor physical performance are prevalent among adult survivors of childhood cancer (survivors). We evaluated the feasibility and effects of resistance training with and without protein supplementation on lean body mass and muscle strength among survivors. METHODS: This double-blind placebo-controlled trial enrolled survivors aged >/=18 to <45 years. Participants were randomized to resistance training with protein supplement (21g whey protein/day, 90kcal) (RT+S) or resistance training with placebo (sucrose, 90kcal) (RT+P). Participants received educational materials, access to a local fitness center, and a tailored resistance training program with tapered supervision. Participant retention and adherence were used to evaluate feasibility. Lean body mass and muscle strength were assessed at baseline and 24-weeks, using dual x-ray absorptiometry, and dynamometer testing or 1-repetition maximum testing, respectively. Mean changes were compared with two-way analysis of variance. RESULTS: Of 70 participants randomized, 57 completed the 24-week intervention (24 in RT+S, 33 in RT+P). RT+S group completed 74.8% and RT+P group completed 67.0% of exercise sessions. Mean age for those who completed was 33.1 years (SD 7.0), 67% were white and 47% female. There were no differences in change in lean mass (RT+S mean 1.05 kg [SD 2.34], RT+P 0.13 kg [SD 2.19], p=0.10) or strength (RT+S mean grip 1.65 kg [SD 4.17], RT+P 1.63 kg [SD 4.47], p=0.98; mean leg press RT+S 58.4 kg [SD 78.8], RT+P 51.0 kg [SD 65.1], p=0.68) between groups. Both lean mass (p=0.03) and strength (grip p=0.003, leg press p<0.001) increased over time. CONCLUSIONS: Supervised resistance training among survivors with protein supplementation is feasible but not more effective at increasing total lean body mass than resistance training alone.