Eight Weeks of Aerobic Exercise Training Improves Fitness, Metabolic Health, Inflammation, and Intestinal Barrier Integrity in Overweight and Obese Women of Different Age Groups

This study investigated the effects of eight weeks of aerobic exercise training on body composition, lipid profiles, organokines (leptin, irisin), inflammatory biomarkers (high-sensitivity C-reactive protein [hs-CRP], interleukin-6 [IL-6]), and intestinal barrier permeability markers (zonulin, lipopolysaccharide-binding protein [LBP]) in overweight and obese women of different age groups. We hypothesized that aerobic exercise would improve cardiorespiratory fitness, body composition, lipid metabolism, and reduce pro-inflammatory responses and intestinal permeability, and that these effects would differ between age groups. A total of 32 participants with a body mass index (BMI) ≥ 23 kg/m² were randomly assigned to one of four groups (<i>n</i> = 8 per group): young exercise (YE), young control (YC), middle-aged exercise (ME), and middle-aged control (MC). The intervention consisted of treadmill running for 50 min per session, four times per week, at an intensity corresponding to 65% of the target heart rate (THR), calculated using the Karvonen formula, for a duration of eight weeks. Body composition variables included body weight, BMI, body fat mass (BFM), percentage body fat (PBF), lean body mass (LBM), and maximal oxygen uptake (VO₂max). Blood samples were analyzed for lipid profiles (total cholesterol [TC], triglycerides [TG], low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C]), organokines, inflammatory markers, and intestinal barrier integrity biomarkers. After the intervention, the YE and ME groups exhibited significant reductions (<i>p</i> < 0.05) in body weight, BMI, BFM, PBF, TC, TG, LDL-C, leptin, hs-CRP, IL-6, zonulin, and LBP. In contrast, LBM and VO₂max significantly increased (<i>p</i> < 0.05) in both exercise groups. No significant changes were observed in irisin concentrations or HDL-C levels (<i>p</i> > 0.05). These results suggest that aerobic exercise training, irrespective of age, is effective in improving cardiorespiratory fitness, body composition, and lipid metabolism, while simultaneously reducing systemic inflammation and is associated with favorable changes in circulating biomarkers of intestinal barrier function in overweight and obese women.