AN AEROBIC COOLDOWN FOLLOWING MORNING, FASTED RESISTANCE EXERCISE HAS LIMITED IMPACT ON POST-EXERCISE HYPERGLYCEMIA IN ADULTS WITH TYPE 1 DIABETES: A RANDOMIZED CROSSOVER STUDY

Abstract

Expert guidelines recommend an aerobic cooldown to lower blood glucose for the management of post-exercise hyperglycemia. This strategy has never been empirically tested. Our objective was to compare the glycemic effects of performing an aerobic cooldown versus not performing a cooldown after a fasted resistance exercise session. We hypothesized that the cooldown would lower blood glucose in the 30 minutes after exercise and would result in less time in hyperglycemia in the 6 hours after exercise. Participants completed two identical resistance exercise sessions. One was followed by a low-intensity (30% VO2peak) 10-minute cycle ergometer cooldown, and the other was followed by 10 minutes of sitting. We compared the changes in capillary glucose concentration during these sessions, and continuous glucose monitoring (CGM) outcomes over 24 hours post exercise. Sixteen participants completed the trial. Capillary glucose was similar between conditions at the start of exercise (p=0.07). Capillary glucose concentration decreased by 0.6 ± 1.0 mmol/l during the 10-minute cooldown but increased by 0.7 ± 1.3 mmol/l during the same time in the no cooldown condition. The resulting difference in glucose trajectory led to a significant interaction (p=0.02) with no effect from treatment (p=0.7). Capillary glucose values at the end of recovery were similar between conditions (p>0.05). There were no significant differences in CGM outcomes. An aerobic cooldown reduces glucose concentration in the post-exercise period, but the small and brief nature of the reduction make this strategy unlikely to be an effective treatment for hyperglycemia occurring after fasted exercise.