Effect of Aerobic and Resistance Exercise on Glycemic Control in Adults With Type 1 Diabetes

Abstract

Objectives: Physical exercise is recommended for individuals with type 1 diabetes, yet the effects of exercise on glycemic control are not well established. We evaluated the impact of different modes of exercise on glycemic control in people with type 1 diabetes.

Methods: In a 3-week randomized crossover trial, 10 adults with type 1 diabetes (4 men and 6 women, aged 33±6 years; duration of diabetes, 18±10 years; glycated hemoglobin level, 7.4%±1%) were assigned to 3 weeks of intervention: aerobic exercise (treadmill at 60% of maximum volume of oxygen utilization), resistance training (8 to 12 repetitions of 5 upper and lower body exercises at 60% to 80% of 1 repetition maximum) or no exercise (control). During each exercise week, participants completed 2 monitored 45 min exercise sessions. For each week of the study, we analyzed participants' insulin pump data, sensor glucose data and meal intake using a custom smart-phone application. The primary outcome was the percentage of time in range (glucose >3.9 mmol/L and ≤10 mmol/L) for the 24 h after each bout of exercise or rest during the control week. The study was registered on ClinicalTrials.gov (NCT:02687893).

Results: Aerobic exercise caused a mean glucose reduction during exercise of 3.94±2.67 mmol/L, whereas the reduction during resistance training was 1.33±1.78 mmol/L (p=0.007). The mean percentage time in range for the 24 h after resistance training was significantly greater than that during the control period (70% vs. 56%, p=0.013) but not after aerobic exercise (60%).

Conclusions: The results indicate that when various confounders are considered, resistance training could improve glycemic control in this population.

Keywords: apport alimentaire; diabète de type 1; dépense énergétique; energy expenditure; exercice; exercise; glycemic control; meal intake; régulation de la glycémie; type 1 diabetes.

Conflict of interest statement

Conflicts of Interest

RR, AW, JEY, KWS and MG have no conflicts of interest with this study. JRC and PGJ have a financial interest in Pacific Diabetes Technologies Inc., a company that may have a commercial interest in the results of this research and technology.

Copyright © 2018 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

Figures

Figure 1:

A: Glycemic response during the in-clinic exercise visits. Sensor glucose data is represented as Mean ± SE during the exercise (represented by box) and 60 min of recovery: ■ resistance training, •, aerobic exercise. * indicate the statistically significant difference between the two interventions based on the paired sample t-tests (p

Figure 2:

Improvements in glycemic outcomes for each study participant are shown in this figure. In the 24 hr. period following RT, all subjects experience positive reductions in mean glucose value and all but one subject experienced reductions in time in hyperglycemia and improvement in time in range compared with the control week. But the same outcomes after AE are not as consistent. In each panel data for each individual subject is shown with ■ indicating resistance training and • indicating aerobic exercise. Inset in each panel is the numerical difference in the outcome measured for the intervention represented in the panel.

Figure 3:

A: Box plots with individual data points indicating the nutritionist estimated energy intake from the meal pictures collected during the 24 hr. period after the in-clinic exercise visit during each intervention week. The energy intake was significantly higher during the 24 hr. after the aerobic and resistance training in-clinic sessions, as indicated by the * based on the randomized mixed effects regression model with a random intercept to account for correlation between observations on the same participant (p