Effects of Three Aerobic Exercise Protocols on Acute Glucose Response and Continuous Glucose Monitoring Trends in Patients with Type 2 Diabetes Mellitus and Stroke: A Randomized Controlled Trial

Objective This study aims to assess the acute and chronic effects of three aerobic exercise protocols, namely, Moderate-Intensity Interval Training (MIIT), Low-to-Moderate Intensity Continuous Training (LMICT), and Reduced-Exertion High-Intensity Training (REHIT), on glycemic control in patients with Type 2 Diabetes Mellitus (T2DM) and stroke. Methods Forty-nine patients diagnosed with both T2DM and stroke were randomly assigned to LMICT, MIIT, REHIT, or the control group. The intervention comprised two phases: from day 3 to day 14 and from day 15 to day 28, with days 1 and 2 designated as a baseline control period. Throughout the intervention, blood glucose levels were continuously monitored and recorded using a Continuous Glucose Monitoring (CGM) system. Results All exercise intervention groups exhibited significant immediate reductions in blood glucose levels following exercise ( t  = 30.68, p  < 0.001). Repeated measures ANOVA demonstrated significant main effects of group and time, as well as a significant interaction, on mean glucose (MG) and time above range (TAR) ( p  < 0.05). Continuous glucose monitoring indicated progressive improvements in MG, time in range (TIR), TAR, peak blood glucose, glucose standard deviation (SD-glucose), and mean amplitude of glycemic excursion (MAGE) in the MIIT group. The REHIT group exhibited significant improvements in peak blood glucose, TIR, TAR, MAGE, SD-glucose, and coefficient of variation (CV) (all p  < 0.01). These trends were not evident in the LMICT group. Notably, the MIIT and REHIT groups exhibited early, significant improvements in MG, peak blood glucose, TIR, and TAR, which preceded subsequent changes in SD-glucose and MAGE relative to controls. Conclusions While all exercise regimens resulted in acute reductions in blood glucose, sustained improvements in overall glycemic control and variability were observed exclusively following the four-week MIIT and REHIT interventions. Specifically, REHIT significantly reduced glucose variability, as reflected by decreases in the CV, whereas MIIT was more effective in lowering MG levels. Conversely, the lower-intensity LMICT regimen (51.23% ± 6.94% heart rate reserve) exerted minimal long-term effects. These findings underscore the potential of moderate- to high-intensity intermittent aerobic training in managing glycemic fluctuations in individuals with T2DM and stroke, thereby emphasizing their clinical relevance. Trial registration: The study was registered with the Chinese Clinical Trial Registry (ChiCTR2200065677, http://www.chictr.org.cn/) on 11/11/2022.