Purpose: This pilot work was conducted to evaluate the effects of neuromuscular electrical stimulation resistance training (RT) of the paralyzed knee extensor muscle groups on skeletal muscle and intramuscular fat (IMF) cross-sectional areas, trunk visceral adipose tissue (VAT), carbohydrate, and lipid profiles in men with spinal cord injury.
Methods: Nine individuals with motor complete spinal cord injury were randomly assigned to an RT + diet group (n = 5) or a diet group (n = 4). The RT + diet underwent 12 wk of progressive RT, twice weekly, to the knee extensor muscle groups using neuromuscular electrical stimulation and ankle weights. Weekly feedback was provided to both groups to maintain a standard diet. Magnetic resonance imaging and a whole-body dual-energy x-ray absorptiometric images were obtained before and 1 wk after interventions. Participants underwent a metabolic study after a 12-h overnight fast to measure fasting and postchallenge plasma glucose, insulin, and lipid profiles.
Results: Skeletal muscle hypertrophy was detected in the whole thigh, knee extensors, and flexors in the RT + diet group compared with the diet group. VAT cross-sectional area, VAT/subcutaneous adipose tissue ratio at L5-S3, and percent IMF decreased significantly in the RT + diet group. Plasma insulin area under the curve decreased in the RT + diet group but not in the diet group. Fasting triglycerides and cholesterol/HDL decreased in the RT + diet group.
Conclusions: Twice-weekly evoked RT to the paralyzed lower extremities resulted in significant skeletal muscle hypertrophy that was associated with reduction in VAT, VAT/subcutaneous adipose tissue ratio, and percent IMF. Significant improvements in insulin profile and lipid metabolism were noted in the RT + diet when compared with diet alone.