Improved Glycemic Control in Adults with Type 2 Diabetes Is More Strongly Associated with Exercise Duration than with Volume, Frequency, or Consistency.

Abstract

Exercise interventions play a pivotal role in managing type 2 diabetes (T2D), yielding significant benefits in glycemic control. Despite the recognized role of exercise duration, volume, frequency, and consistency, the literature remains discrepant on which exerts the greatest effect. The purpose of this secondary analysis was to determine the relationship between exercise duration, volume, frequency, and consistency and markers of glycemic control (HbA1c and continuous glucose monitoring metrics) following a 26-wk mHealth intervention. Inactive adults with newly diagnosed (<2 yr) T2D ( n = 58) completed blood and 14-day continuous glucose monitoring testing before and after a 26-wk personalized exercise intervention. Raw exercise data from fitness watches were extracted for each session. Duration, volume, frequency, and consistency were calculated for the full intervention and for the first 13 wk (greater support) and last 13 wk (reduced support). Average session duration (57 ± 36 min) significantly predicted HbA1c (β = -0.23 [0.07], P = 0.002), 24-h mean glucose (β = -0.03 [0.01], P = 0.01), and glycemic variability (standard deviation; β = -0.01 [0.0], P = 0.003; Beta coefficients are reported with standard errors). Total exercise time during the first 13 wk (2931 ± 3362 min) also predicted HbA1c (β = -0.001 [0.0], P = 0.01), mean glucose (β = -0.002 [0.0], P = 0.01), and glycemic variability (β = -0.005 [0.0], P = 0.03). No other exercise metrics significantly predicted outcomes. Average session duration and exercise time accumulated early in the intervention were the only significant predictors of improvements in HbA1c, mean glucose, and glucose variability. These findings suggest that promoting increased exercise duration, independent of type or intensity, may improve glycemic control among individuals with newly diagnosed T2D. ClinicalTrials.gov NCT04653532.