We showed that isoflavones and exercise improve total and abdominal fat mass (FM) to a greater extent than does exercise alone in postmenopausal women, but not other cardiovascular disease (CVD) risk factors. Fat-free mass (FFM) showed a wide variability of responses, with 60% of women having increased FFM and 40% having decreased FFM. We thus wondered if women who had decreased FFM could be considered as nonresponders (NRs) to exercise and if this masked a potential synergistic effect of phytoestrogens (PHY) and exercise. The aim of this study was to verify if PHYs enhance the response obtained after aerobic and resistance exercises in CVD risk profile in exercise responders.
Among 21 women who participated in a 6-month exercise program and received PHY or placebo (PLA), 14 were exercise responders (PHY, n = 8; PLA, n = 6) whereas 7 were NRs. Body weight, waist circumference, FM, and FFM were assessed (dual-energy x-ray absorptiometry). Plasma glucose, insulin, sex hormone-binding globulin, and testosterone levels were obtained after a 12-hour overnight fast. Total energy intake was measured with a 3-day dietary record. All measurements were performed before and after the intervention.
After exercise training, the PHY and PLA groups, but not the NR group, had increased FFM (0.01 < P < 0.03). On the other hand, body weight, FM, and systolic and diastolic blood pressure (0.01 < P < 0.05) decreased in the PHY group only. Furthermore, plasma insulin level (P = 0.04) and homeostasis model assessment significantly decreased (P = 0.03) while plasma sex hormone-binding globulin increased (P = 0.04) after training in the PHY group, whereas energy intake remained unchanged in both groups (0.10 < P < 0.59) after the intervention.
PHYs combined with exercise compared with exercise alone seem to improve body composition and CVD risk profile in exercise-responder women.