The Impact Of Exercise Intensity On Glycemic Control Following Removal Of Exercise

The detrimental effects of exercise cessation on free-living glycemic control (GC) in habitually active individuals are well established. However, the role of exercise intensity to mitigate GC impairment after exercise cessation is not well understood. PURPOSE: To examine if exercise intensity differentially influences the negative impact of exercise cessation on GC. METHODS: This randomized, cross over study design recruited nine healthy, recreationally active participants (Age: 26 ± 2 years, BMI: 25.2 ± 1.1 kg/m2, VO2Peak: 39.8 ± 2.0 ml/kg/min) to complete two isocaloric (300 kcals/session) bouts of exercise at moderate (Mod EX: 55-60 %HRR) or vigorous (High EX: 75-80 %HRR) intensity followed by 3 days of exercise removal (No EX). GC was measured via a continuous glucose monitoring system throughout both phases. Other than a standardized breakfast, participants were not provided food. Participants were instructed to consume the same type and volume of food each day across and between phases. RESULTS: Physical activity was lower during the No EX phases compared to the exercise phases (Mod EX: 10,714 ± 962 steps/day, 65 ± 7 moderate physical activity (MPA) minutes, 11 ± 4 vigorous physical activity (VPA) minutes; Mod No EX: 5480 ± 817 steps/day, 29 ± 5 MPA minutes, 4 ± 4 VPA minutes), (High EX: 10,246 ± 1021 steps/day, 54 ± 6 MPA minutes, 15 ± 4 VPA minutes, High No EX: 5867 ± 973 steps/day, 34 ± 7 MPA minutes, 4 ± 4 VPA minutes), p < 0.05. 24-hour average blood glucose (Mod EX: 90 ± 4, Mod No EX: 94 ± 3, High EX: 87 ± 4, High No EX: 98 ± 3; mg/dL) and average peak post prandial blood glucose (Mod EX: 131 ± 12, Mod No EX: 134 ± 7, High EX: 127 ± 10, High No EX: 141 ± 7; mg/dL) demonstrated no significant main effect of exercise intensity (p > 0.05), but did demonstrate a significant main effect of phase (p < 0.05). CONCLUSIONS: Removal of exercise for 3 days impairs free-living glycemic control, and exercise intensity does not appear to differentially modulate this response. Supported by: American Heart Association AIREA (award #: 953463)