Effect of exercise training on body temperature in the elderly: a retrospective cohort study

Abstract

Background Although rise in body temperature in the elderly has clinical benefits such as activating immune system, little is known regarding the mediator related to the elevation of body temperature. This study evaluated the effect of exercise training on body temperature and clarified the relationship between body temperature and body composition in the elderly. Methods In this retrospective cohort study, a total of 91 elderly participants performed aerobic and anaerobic exercise training twice a week for 2-year. Non-contact infrared thermometer and bioelectrical impedance analysis were performed at baseline and at 2-year. The participants were divided into 2 groups by baseline body temperature of 36.3℃; lower body temperature group (n = 67) and normal body temperature group (n = 24). Results Body temperature rose significantly after exercise training (36.04 ± 0.01 °C to 36.30 ± 0.02 °C, p < 0.0001) in the lower body temperature group, whereas there was no significant difference (36.35 ± 0.02 °C to 36.36 ± 0.03 °C, p = 0.39) in the normal body temperature group. A positive correlation was observed between the amount of change in body temperature and baseline body temperature (r = -0.68, p < 0.0001). Increase in skeletal muscle mass was an independent variable related to the rise in body temperature by the multivariate logistic regression analysis (odds ratio: 4.77, 95% confidence interval: 1.29–17.70, p = 0.02). Conclusions Exercise training raised body temperature in the elderly, especially those with lower baseline body temperature.