Objectives
This study aimed to examine the effectiveness of resistance training on hemoglobin A1c (HbA1c) levels and body mass index in patients with diabetes mellitus, categorized by age.
Methods
A comprehensive search of English-language literature published between 1997 and 2025 was performed across 6 databases (Embase, CINAHL, Medline, Cochrane, PubMed, and PEDro). Standardized mean differences and 95% confidence intervals were calculated, and publication bias was assessed using funnel plots and Egger’s test. The Joanna Briggs Institute checklist was applied to evaluate study quality.
Results
Thirty randomized controlled trials met the inclusion criteria, comprising 620 participants in the older (<60 years of age) subgroup and 1,389 in the middle-aged (40–59 years of age) subgroup. In both subgroups, resistance training significantly reduced HbA1c levels and body mass index, while increasing muscle strength (primary outcome). It also significantly increased high-density lipoprotein, improved VO₂ peak, and reduced low-density lipoprotein (secondary outcomes). However, the effects of resistance training were significant only in the older-adult subgroup for total cholesterol and only in the middle-aged subgroup for triglycerides.
Conclusion
Resistance training is a recommended rehabilitation exercise for patients with diabetes mellitus. Routine resistance training has been shown to help maintain optimal HbA1c and body mass index levels and improve muscle strength. In addition, it does not pose a risk of adverse events in either middle-aged or older patients. Nonetheless, patients are advised to monitor blood glucose levels and adhere to a proper diet to achieve optimal outcomes.