Skeletal Muscle Hypertrophy and Cardio-Metabolic Benefits After Spinal Cord Injury

Primary Objectives Aim #1: To determine the impact of 12+12 weeks of neuromuscular electrical stimulation (NMES)+FES-LEC on oxygen uptake, insulin sensitivity and glucose uptake in adults with SCI compared to control + FES-LEC. Aim #2: To determine the impact of 12+12 weeks of NMES+FES-LEC on skeletal muscle size, infiltration of intramuscular fat, visceral adiposity as well as fatigue resistance compared to control+ FES-LEC. . Aim #3 : To determine the impact of 12+12 weeks of NMES+FES-LEC on determinants of energy metabolism, protein molecules involved in insulin signaling, muscle hypertrophy and oxygen uptake (IRS-1, adenosine monophosphate kinase (AMPK), glucose transporter (GLUT-4), insulin like growth factor (IGF-1), Akt, mammalian target of rapamycin (mTOR) and Peroxisome proliferator-activated receptor coactivator (PGC-1 alpha) and electron transport chain proteins compared to control + FES-LEC only. Subjects: Forty eight chronic (1 year or more post-injury) individuals with motor complete SCI will be recruited from the Hunter Holmes McGuire VA Spinal Cord Dysfunction registry and Virginia Commonwealth University over 4 years. Inclusion Criteria 1. All participants will be between 18-65 years old, men/women, 2. greater than one year post SCI, 3. Body mass index (BMI) \< 30 Kg/m2. 4. Participants must have C5-L2 level of injury, traumatic motor complete or incomplete SCI \[American Spinal Injury Impairment Scale Classification (AIS A, B or C)\]. Exclusion Criteria: 1. Participants with any of the following pre-existing medical conditions will be excluded (cardiovascular disease, uncontrolled type II diabetes mellitus, uncontrolled hypertension, and those on insulin, pressures sores stage 3 or greater), hematocrit above 50% or urinary tract infection or symptoms. 2. Participants with osteoporosis (T-score equal or worse than -2.5 according to the World Health recommendation) will be excluded. 3. Pregnant women and women who will be involved and become pregnant during the course of the study will be excluded as well. Study arms 1. NMES+FES group (n =24; 2 days/week for 24 weeks); this group will undergo twice weekly of 12 weeks of surface NMES and ankle weights followed by 12 additional weeks of twice weekly of progressive FES-LEC using the RT300 bike. The total participation duration is 24 weeks +3 weeks for measurements. 2. Control + FES group (n =24; 2 days/week for 24 weeks); this group will undergo twice weekly of 12 weeks of passive leg extension/flexion with no ankle weights followed by 12 additional weeks of twice weekly of progressive FES-LEC using the RT300 bike. The total participation duration is 24 weeks+3 weeks for measurements.