The Effect of Exercise Training and Soy-isoflavone Supplementation on Menopausal Symptoms

Abstract

Exercise training and soy isoflavone (phytoestrogen) supplementation may each have small effects for alleviating menopausal symptoms. PURPOSE: To assess the effects of a relatively long duration of exercise training combined with soy isoflavone supplementation (2 years) on menopausal symptoms. METHODS: 191 postmenopausal women (age 56 SD 6 y) who reported having hot flushes/night sweats, insomnia, numbness in the limbs, fatigue, or headaches two or more times per week were randomized to: 1) Exercise (strength training twice a week and walking four times per week); 2) Isoflavone supplementation (157 mg/d); 3) Exercise + isoflavone supplementation; or 4) Placebo for two years. The frequency (times per week), duration (minutes), and severity (0 = no symptoms, 1 = mild, 2 = moderate, 3 = severe) of each of hot flushes/night sweats, insomnia, numbness in the limbs, fatigue, and headache were assessed by a menopausal symptoms questionnaire (St. Germain et al. 2001) before and after the interventions. Data for each symptom were analyzed by multivariate analyses of variance, with exercise group, isoflavone supplementation, and time as factors, followed by univariate tests if multivariate analysis was significant. RESULTS: Multivariate analyses indicated a significant exercise by time interaction for insomnia (p=0.05) and a significant isoflavone by time interaction for headaches (p<0.05). Univariate tests indicated that exercise groups decreased insomnia duration (exercise: 64 SD 49 minutes at baseline vs. 51 SD 49 minutes at 2 years) compared to non-exercise groups (64 SD 50 minutes at baseline vs. 69 SD 49 minutes at 2 years) (p<0.05), and isoflavone groups decreased headache intensity (1.6 SD 0.7 at baseline vs. 0.9 SD 0.7 at 2 years) and duration (114 SD 362 minutes at baseline vs. 79 SD 323 minutes at 2 years) compared to non-isoflavone groups (intensity of 1.8 SD 0.7 at baseline vs. 1.6 SD 0.7 at 2 years, and duration of 251 SD 361 minutes at baseline vs. 298 SD 323 minutes at 2 years) (p<0.01). CONCLUSION: Exercise training reduced insomnia duration and isoflavone supplementation reduced headache intensity and duration in postmenopausal women. Neither exercise training nor isoflavone supplementation affected hot flushes/night sweats, limb numbness, or fatigue. Supported by the Canadian Institutes of Health Research