A 12-week cycling program improves glucose homeostasis, lipid profile, and body composition in women with insulin resistance: a pilot study.

This study evaluated the effects of a cycling intervention on glucose homeostasis, lipid profile, and body composition in individuals with insulin resistance and excess body weight. Seven women participants completed a 12-week supervised cycling program (20-30 min/day, 3 days/wk). Body composition assessments and biochemical analyses, including oral glucose tolerance tests, triglycerides, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and non-high-density lipoproteins, were conducted pre- and post-intervention. Paired t-tests and Hedge's g assessed changes in body composition, lipid profile, and homeostatic model assessment for insulin resistance (HOMA-IR), while a 2×4 repeated-measures analyses of variance (ANOVA) analyzed exercise- and time-related effects on glucose and insulin. Post-intervention, significant moderate reductions were observed in body fat mass (p = 0.020, g = -0.52), body fat percentage (p = 0.006, g = -0.55), visceral fat area (p = 0.005, g = -0.64), and waist-to-hip ratio (p < 0.001, g = -0.87). A significant, small reduction in non-high-density lipoproteins was also noted (p = 0.016, g = -0.34). A 2×4 repeated-measures ANOVA revealed a significant effect of exercise on glucose concentration (p = 0.031; η2 p = 0.640, moderate), with lower post-exercise levels. Additionally, a significant time×exercise interaction was observed for insulin concentration (p = 0.009; η2 p = 0.30, moderate). Follow-up tests comparing pre to post-exercise changes revealed significant decreases in insulin levels at 30-min (p < 0.001), 60-min (p = 0.008), and 120-min (p = 0.011) postload. These findings suggest a 12-week cycling intervention improves glucose homeostasis, lipid profile, and body composition in overweight women with insulin resistance.