Effects of volume-matched resistance training with different loads on glycemic control, inflammation, and body composition in prediabetic older adults.

The purpose of the investigation was to examine the influence of resistance training (RT) with equal volume and varying load on glycemic control, inflammation, and body composition in non-obese prediabetic older adults. Non-obese older adults with prediabetes were randomized into 2 groups, high-load (80% of 1RM) and low-load (40% of 1RM) RT (n = 12/group), both with the same training volume. Oral glucose tolerance test (OGTT) and blood samples were collected at baseline and again after 10 weeks of RT. Fasting blood glucose (103.8 vs. 99.9 mg/dL) and the area under the curve (AUC) of OGTT (0-30 min) decreased significantly in older adults with prediabetes after 10 weeks of volume-matched RT (p < 0.05). Serum levels of MCP-1 (138.7 vs. 98.5 pg/mL) and TNF-α (1.8 vs. 1.3 pg/mL) showed significant decrease after 10 weeks of high-load RT (p < 0.05). There were no changes in IL-10, IL-6, and CRP levels in both groups. Leptin showed significant decrease after 10 weeks of low-load RT (p < 0.05). Changes in fasting glucose and AUC of OGTT (0-120 min) were positively correlated with changes in MCP-1 and TNF-α (p < 0.05). Lean body mass (39.6 vs. 40.3 kg) increased significantly after 10 weeks of volume-matched RT (p < 0.05). Results indicate that equal-volume RT at different loads is beneficial to glycemic control and muscle growth, and high-load RT shows more prominent anti-inflammatory effects. Novelty: Short-term high-load resistance training can help older adults bring their blood sugar level back to normal. High-load resistance training attenuates aging-associated chronic inflammation.