The optimal exercise modality and dose for glycemic control in older adults with type 2 diabetes mellitus: a...

While exercise remains an essential part of managing type 2 diabetes mellitus (T2DM), evidence remains limited regarding which exercise modalities and doses provide the greatest benefit for glycemic control in older adults. Accordingly, we assessed the effects of exercise modality and dose on glycated hemoglobin (HbA1c), fasting blood glucose (FBG), and 2-hour postprandial glucose (2hPG) in older adults with T2DM.

We searched seven databases from inception to 18 August 2025. Eligible studies were RCTs involving adults with T2DM in which the mean participant age was at least 60 years. Under a Bayesian framework, we conducted a random-effects network meta-analysis combined with dose-response modeling, using MET-min/week as the standardized metric for exercise dose, to assess the effects of exercise on glycemic control in older adults.

Thirty-four RCTs involving 2461 participants were ultimately included. The intervention network comprised continuous aerobic exercise (CAE), combined aerobic and resistance exercise (CE), traditional Chinese sports (TCS), resistance exercise (RE), high-intensity interval training (HIIT), and control group (CG). For HbA1c, CE (MD = -1.05%; 95% CrI: -1.43, -0.64), TCS (MD = -0.80%; 95% CrI: -1.09, -0.52), HIIT (MD = -0.63%; 95% CrI: -1.07, -0.19), CAE (MD = -0.48%; 95% CrI: -0.74, -0.24) and RE (MD = -0.44%; 95% CrI: -0.80, -0.08) showed greater reductions than CG. The SUCRA ranking probabilities favored CE for HbA1c (SUCRA = 94.86%). For FBG, significant reductions versus CG were observed for CE (MD = -1.44 mmol/L; 95% CrI: -2.16, -0.66), CAE (MD = -0.98 mmol/L; 95% CrI: -1.52, -0.41), and TCS (MD = -0.77 mmol/L; 95% CrI: -1.30, -0.23). Ranking probabilities favored CE (SUCRA = 88.03%). In the overall dose-response analyses, significant improvements began at approximately 520 MET-min/week for HbA1c and 500 MET-min/week for FBG. For 2hPG, evidence was limited. Only CE showed a significant reduction versus CG (MD = -3.15 mmol/L; 95% CrI: -5.42, -0.83), and no dose-response analysis was performed because of sparse evidence.

Exercise interventions improved glycemic control in older adults with T2DM, and CE appeared to show a favorable overall profile across glycemic outcomes. Total exercise volume showed nonlinear dose-response relationships with HbA1c and FBG. Further well-designed studies are needed to confirm these dose-response patterns, refine dose ranges for specific exercise modalities, and support more individualized exercise strategies.

https://www.crd.york.ac.uk/PROSPERO/view/CRD420251127345, identifier CRD420251127345.