Combined aerobic and resistance training, and incidence of diabetes: A retrospective cohort study in Japanese older women

AIMS/INTRODUCTION: To investigate the relationship between combined aerobic and resistance training, and the incidence of type 2 diabetes mellitus. MATERIALS AND METHODS: The present study included 10,680 Japanese women. Participants enrolled between 2005 and 2010, and were followed up until 2014. The frequency of combined training was counted for the first 3 months, the 6th month and the 9th month. In 2014, women reported whether or not they had diabetes, as well as the year of developing diabetes. Hazard ratios and 95% confidence intervals (CI) for the incidence of type 2 diabetes were obtained using Cox proportional hazard models. RESULTS: The median duration of follow up was 5 years, with 166 women developing type 2 diabetes. Using the lowest frequency of training group (1st quartile) as the reference, the hazard ratios for the second through fourth quartiles was as follows: 0.95 (95% CI 0.64–1.41), 0.73 (95% CI 0.48–1.13) and 0.69 (95% CI 0.44–1.07), respectively (P for trend = 0.116). After adjustment for age, body mass index and thigh circumference, the hazard ratios were: 0.84 (95% CI 0.56–1.26), 0.69 (95% CI 0.45–1.06) and 0.61 (95% CI 0.39–0.95), respectively (P for trend = 0.040). CONCLUSIONS: A higher frequency of combined aerobic and resistance training is associated with a lower risk of developing type 2 diabetes in Japanese women.