Total Energy Cost of a Single Bout of Circuit Resistance Exercise in Persons with Spinal Cord Injury

Abstract

PURPOSE: Circuit resistance training (CRT) in persons with spinal cord injury (SCI) has been shown to satisfy minimum physical activity recommendations, increase aerobic fitness and muscular strength, better the atherogenic lipid profile, and lessen upper extremity pain in persons with paraplegia and tetraplegia. However, the total energy (kilocalorie) cost of a single CRT session, including excess post-exercise oxygen consumption (EPOC), was previously unknown METHODS: Nine persons with chronic traumatic paraplegia underwent a 40 - 45 min CRT exercise which interspersed arm cycle ergometry between resistance maneuvers to amount 3 × 10 repetitions at 60% of maximum for 6 upper body lifts and 20 min of arm cycling. Pulmonary gas exchange data were collected before and during exercise, and up to 120 min post-exercise and used to calculate total energy expenditure, substrate preference, and rates of carbohydrate and fat oxidation. Data from the CRT session was compared a non-exercise control condition (CON RESULTS: During the 42 ± 4 min CRT bout participants worked at 63 ± 11% and 78 ± 9% of their maximal rate of oxygen consumption (VO2) and heart rate (HR), respectively, and expended 166 ± 55 kcal. Compared to control, EPOC following CRT was significantly elevated by 11% during the 120 min post-exercise measurement period. Respiratory exchange ratio (RER) during the post-exercise period was 0.74 ± 0.07 and 0.83 ± 0.04 for CRT and CON, respectively, representing a shift in resting substrate preference toward fat oxidation following CRT. Accordingly, during this time nearly twice as many grams of fat were oxidized in CRT vs CON (14.0 vs 7.5 g fat). A total of 322 ± 21 kcal were expended in response to exercise and recovery. CONCLUSION: These data demonstrate that if performed thrice weekly, CRT requires energy expenditure sufficient to meet authoritative weekly guidelines for caloric expenditure that promote general health.