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Abstract

Chronic inflammation has been implicated in the pathogenesis of several chronic diseases, such as atherosclerosis and diabetes, as well as certain types of cancers. It has been suggested that circulating biomarkers for inflammation may be modified by exercise; however, few laboratory-based studies have been conducted in nonobese premenopausal women. The purpose of this investigation was to determine the impact of a 4-month exercise training and caloric-restriction intervention with the goal of weight loss on circulating biomarkers of inflammation in sedentary premenopausal women aged 25- 40 years (weight, 57 ± 2 kg). Subjects were studied for 6 consecutive menstrual cycles: 1 Screening, 1 Baseline, then 4 interventions (Interventions 1-4). Supervised aerobic training, consisting primarily of treadmill running and elliptical machine exercise, was performed 4 times per week for 40-90 min at 79% ± 0.7% of maximal heart rate. Subjects also consumed 30% fewer calories vs. baseline (1863 ± 58 to 1428 ± 53 kcalday(-1) (1 kcal = 4.186 kJ), p < 0.0001). Circulating inflammatory biomarkers, including adiponectin, high-sensitivity (hs) C-reactive protein (CRP), tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interferon-gamma (IFN-γ), and leptin, as well as body composition, aerobic capacity, and energy balance, were measured before and after the intervention. Maximal aerobic capacity increased by 8.5 ± 1.7 mL kg(-1)min-1 (p < 0.001) and body mass declined by an average of 3.7 ± 0.5 kg (p < 0.001). Significant reductions in IL-6 (0.39 ± 0.04 to 0.30 ± 0.03 pgmL(-1), p = 0.025), IFN-γ (0.58 ± 0.83 to 0.42 ± 0.64 pgmL-1, p = 0.030), and leptin (13.18 ± 1.28 to 6.28 ± 0.71 pgmL(-1), p < 0.001) were detected in response to the intervention. No significant changes in adiponectin, hs-CRP, or TNF-α were found. Weight loss in response to exercise training and caloric restriction is effective in reducing inflammatory markers, specifically IL-6 and leptin.