Abstract
In persons with a spinal cord injury (SCI), resistance training using neuromuscular electrical stimulation (NMES-RT) increases lean mass in the lower limbs. However, whether protein supplementation in conjunction with NMES-RT further enhances this training effect is unknown. In this randomized controlled pilot trial, 15 individuals with chronic SCI engaged in 3 times/week NMES-RT, with (NMES+PRO, n = 8) or without protein supplementation (NMES, n = 7), for 12 weeks. Before and after the intervention, whole body and regional body composition (DXA) and fasting glucose and insulin concentrations were assessed in plasma. Adherence to the intervention components was ≥96%. Thigh lean mass was increased to a greater extent after NMES+PRO compared to NMES (0.3 (0.2, 0.4) kg; p < 0.001). Furthermore, fasting insulin concentration and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) were decreased similarly in both groups (fasting insulin: 1 [-9, 11] pmol∙L(-1); HOMA-IR: 0.1 [-0.3, 0.5] AU; both p ≥ 0.617). Twelve weeks of home-based NMES-RT increased thigh lean mass, an effect that was potentiated by protein supplementation. In combination with the excellent adherence and apparent improvement in cardiometabolic health outcomes, these findings support further investigation through a full-scale randomized controlled trial.