Effects of exercise mode on postprandial metabolism in humans with chronic paraplegia: Exercise and postprandial metabolism in SCI

Purpose: The purpose of this study was to assess the acute effects of exercise mode and 3 intensity on postprandial macronutrient metabolism. Methods: Ten healthy males age 39 ± 10 yr with chronic paraplegia (13.2 ± 8.8 yr, ASIA A-C) completed 3 isocaloric bouts of upper body exercise and a resting control. Following an overnight fast, participants completed circuit resistance exercise (CRE) first and the following conditions in a randomized order, separated by >48 h: i) control (CON), ~45 min seated rest; ii) moderate intensity continuous exercise (MICE), ~40 min arm cranking at a resistance equivalent to ~30% peak power output (PPO) and; iii) high intensity interval exercise (HIIE), ~30 min arm cranking with resistance alternating every 2 min between 10% PPO and 70% PPO. After each condition, participants completed a mixed meal tolerance test (MMTT) consisting of a 2,510 kJ liquid meal (35% Fat, 50% Carbohydrate, 15% Protein). Blood and expired gas samples were collected at baseline and regular intervals for 150 min post-meal. Results: An interaction (P<.001) was observed with rates of lipid oxidation elevated above CON in HIIE until 60 min post-meal and in CRE at all postprandial time points up to 150 min post-meal. Postprandial blood glycerol was greater in MICE (P=.020) and CRE (P=.001) compared to CON. Furthermore, non-esterified fatty acid area under the curve had a moderate-to-strong effect in CRE vs MICE and HIIE (Cohen’s d: -.76 and -.50, respectively). Conclusion: In persons with paraplegia, high intensity exercise increased postprandial energy expenditure independent of the energy cost of exercise. Furthermore, exercise combining resistance and endurance modes (CRE) showed the greater impact on postprandial Lox.