Metabolic response to 6-week aerobic exercise training and dieting in previously sedentary overweight and obese pre-menopausal women: A randomized trial

BackgroundThe aim of this study was to compare 6 weeks short-term moderate intensity aerobic exercise and dieting on serum metabolomics and cardio-metabolic risk factors in pre-menopausal women.MethodsNinety previously inactive overweight and obese (BMI 25–35 kg/m2) women (age 41.5 ± 7.6 years) were randomized to either a 6-week Nordic walking exercise program (EX, n = 45) or dietary counseling group (DI, n = 45). Body composition, serum glucose, insulin and lipids were measured. Serum low-molecular-weight metabolites and lipid constituents were analyzed by nuclear magnetic resonance spectroscopy. Measurements were done at baseline and 7 days after the last training session.ResultsSix weeks aerobic exercise program yielded reductions in serum free fatty acids (−34.7%, 95% confidence interval (CI), −50 to −18, p < 0.001), glucose (−9.6%, 95%CI, −15 to −4, p < 0.001) and homeostasis model assessment of insulin resistance (HOMA-IR) (−28.7%, 95%CI, −48 to −10, p = 0.005) without changes in body weight or fat mass. Diet counseling resulted in loss of body weight (1.5%, 95%CI, −2.3 to −0.7, p = 0.001) but no changes in free fatty acids, fasting glucose, or HOMA-IR were found.ConclusionOur results indicate that small weight loss does not produce measurable health benefits, whereas short-term regular aerobic exercise can improve glucose and lipid metabolism even in the absence of weight loss in previously sedentary overweight and obese women.