Impact of 12-week combined resistance-aerobic training on HbA1c levels and WHOQOL in type 2 diabetes mellitus: A randomized controlled trial

Type 2 diabetes mellitus (T2DM) is characterized by long-term hyperglycemia, decreased muscle strength, and impaired quality of life. Although aerobic exercise and resistance training separately enhance glycemic parameters, the combined use of both types of training may exert additive effects on metabolic and psychosocial status. This investigation assessed the impacts of a 12-week combined resistance–aerobic training protocol on glycosylated hemoglobin (HbA1c) and quality of life (WHOQOL-BREF) in adults with T2DM. In this two-arm single-blind randomised controlled trial, 80 adults with T2DM (mean age: 53.1 ± 5.7 years; mean duration of T2DM: 8.9 ± 3.4 years) were randomly assigned to receive Combined Resistance-Aerobic Training (CRAT; n = 40) or Standard Care (SC; n = 40). The CRAT group received supervised resistance (60–70 % 1-RM, 8–10 exercises) and aerobic training (brisk walking or cycling at 60–75 % HRmax) three times a week for 12 weeks. Primary outcome was HbA1c; secondary outcomes were fasting glucose, BMI, and WHOQOL-BREF domains (physical, psychological). Assessments were at baseline, Week 12 (post-intervention), and Week 24 (follow-up). HbA1c decreased significantly in the CRAT group from 8.4 ± 0.9 % to 7.1 ± 0.6 % ( p < 0.001), whereas SC had lesser improvement (8.3 ± 0.8 % to 7.9 ± 0.7 %, p = 0.04). Between-group difference at Week 12 was significant ( p < 0.001). WHOQOL-BREF total score improved from 54.3 ± 7.2 to 71.6 ± 6.9 in CRAT ( p < 0.001), with the highest improvements in physical (Δ = +20.5 %) and psychological (Δ = +18.3 %) areas. All gains were sustained at Week 24. Effect sizes were large for HbA1c (d = 0.85) and moderate to large for WHOQOL-BREF areas (d = 0.60–0.78). No adverse effects were reported. Twelve weeks of concurrent resistance-aerobic training considerably enhanced glycemic control and overall quality of life in adults with T2DM compared with usual care. Incorporation of organized multimodal exercise into programs of diabetes rehabilitation may provide a practical and promising approach to improve metabolic and psychosocial outcomes.