Effects of postprandial exercise timing on blood glucose and fluctuations in patients with type 2 diabetes mellitus.

Background: The aim of this study was to assess how moderate-intensity aerobic exercise performed 45 minutes and 90 minutes after a meal affects blood glucose levels and fluctuations in individuals diagnosed with type 2 diabetes mellitus (T2DM).

Methods: Twenty-two patients with T2DM, who were solely receiving oral hypoglycemic medication, were enrolled and divided randomly into two categories: those exercising 45 minutes after a meal (45-minute postprandial exercise group) and those exercising 90 minutes post-meal (90-minute postprandial exercise group). Both groups engaged in a 30-minute session of moderate-intensity aerobic stationary bike exercise following breakfast. This aerobic exercise regimen consisted of two stages, with the groups switching exercise timings after the initial phase. Continuous glucose monitoring (CGM) was utilized to evaluate the blood glucose levels and fluctuations in the participants.

Results: After breakfast, both overall daily blood glucose levels and the area under the curve for blood glucose following breakfast were reduced in the 45-minute postprandial exercise group compared to the 90-minute postprandial exercise group. The 45-minute postprandial exercise group demonstrated greater time spent within the target glucose range and less time above the target range than the 90-minute postprandial exercise group. Additionally, measures such as standard deviation, mean amplitude of glycemic excursions, largest amplitude of glycemic excursions, and postprandial glucose excursion for breakfast, peak postprandial glucose levels, and duration of elevated glucose levels were all lower in the 45-minute postprandial exercise group compared to the 90-minute postprandial exercise group.

Conclusions: Moderate-intensity aerobic exercise lasting 45 minutes after meals was found to be more efficient in decreasing blood glucose levels and minimizing fluctuations compared to exercising 90 minutes after meals in patients with T2DM. Additionally, it notably reduced the peak in blood glucose levels after meals.