Evaluating the Effect of a Ten-Minute Aerobic Cooldown on the Blood Glucose Response of Adults with Type 1 Diabetes Following Fasted Resistance Exercise

• Author / Creator

  McClure, Reid D

• Abstract
  Introduction: Despite the health promoting effects of physical activity and exercise, people with type 1 diabetes (T1D) are less active than people without diabetes. This disparity is partly due to the risk of hypoglycemia and the tedious steps required to prevent or treat hyperglycemia during activity, as well as a corresponding fear of hypoglycemia and potentially severe adverse outcomes. One strategy to prevent hypoglycemia from activity is to perform moderate to high intensity resistance exercise, while fasted in the morning, as it is associated with blood glucose concentration increases. However, increasing blood glucose concentration can lead to hyperglycemia, which could increase the risk of developing diabetes-related complications and typically requires food intake to be delayed until glucose concentration has returned to target range. One potential strategy to treat exercise-induced hyperglycemia, which is currently recommended in international guidelines, is to perform a brief aerobic cooldown, but has never been empirically tested. Our objective was to investigate the effect on blood glucose concentration from performing a cooldown after fasted resistance exercise by comparing the change in capillary glucose that occurs when a 10-minute aerobic cooldown is performed immediately after fasted resistance exercise compared to no cooldown.

  Methods: Sixteen participants with T1D completed two 45-minute fasted resistance exercise sessions consisting of 7 exercises performed for 3 sets of 8 repetitions at 8 repetition maximum. One session was followed immediately by a 10-minute cycle ergometer cooldown at 30% of VO2peak before 20 minutes of seated recovery, and the other was followed by 30 minutes of seated recovery. We measured capillary glucose before, during, and after exercise, and used 2x3 repeated measures ANOVA to determine the effect of the cooldown during the 30-minute recovery period. We investigated post-exercise glucose trends using continuous glucose monitoring (CGM) data from the 6- and 24-hour post-exercise as well as overnight period. We compared CGM data by Wilcoxon signed rank test.

  Results: ANOVA analysis detected a significant interaction of time and treatment during the 30 minute recovery period due to a brief decline in capillary glucose of -0.6  1.0 mmol/l during the 10-minute cooldown, but an increase of 0.7  1.3mmol/l during the same period when no cooldown was completed. However, the decrease from the cooldown was not sufficient or long-lasting enough to prevent glucose concentration from increasing, as during the last 20 minutes of the 30-minute recovery period, capillary glucose increased in both conditions. CGM data showed no significant differences when comparing conditions with 24-hour mean glucose of 8.7 mmol/l (7.46, 9.36) and 9.2 mmol/l (8.21, 10.68) during cooldown and no cooldown conditions, respectively. The time in hyperglycemic range was high for 6 hours after both conditions when compared to the guideline recommended targets of 25%, with 35% (10, 60) and 36% (10, 61) for cooldown and no cooldown respectively.

  Conclusion: Performing a cooldown decreases post-exercise glucose concentration, but alone does not effectively treat or prevent hyperglycemia in the post-exercise period. Future studies should investigate the use of a cooldown as an adjunct to insulin correction to treat hyperglycemia following fasted exercise.

• Subjects / Keywords

  • Type 1 Diabetes
  • Fasted Resistance Exercise
  • Cooldown

• Graduation date

  Fall 2023

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-b627-a107

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.