McMullan Rachel C, Kelly Scott A, Hua Kunjie, Buckley Brian K, Faber James E, Pardo-Manuel de Villena Fernando, Pomp Daniel
Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
Department of Zoology, Ohio Wesleyan University, Delaware, Ohio.
Physiol Rep. 2016 Nov;4(21). doi: 10.14814/phy2.13011. Epub 2016 Nov 14.
Aging is associated with declining exercise and unhealthy changes in body composition. Exercise ameliorates certain adverse age-related physiological changes and protects against many chronic diseases. Despite these benefits, willingness to exercise and physiological responses to exercise vary widely, and long-term exercise and its benefits are difficult and costly to measure in humans. Furthermore, physiological effects of aging in humans are confounded with changes in lifestyle and environment. We used C57BL/6J mice to examine long-term patterns of exercise during aging and its physiological effects in a well-controlled environment. One-year-old male (n = 30) and female (n = 30) mice were divided into equal size cohorts and aged for an additional year. One cohort was given access to voluntary running wheels while another was denied exercise other than home cage movement. Body mass, composition, and metabolic traits were measured before, throughout, and after 1 year of treatment. Long-term exercise significantly prevented gains in body mass and body fat, while preventing loss of lean mass. We observed sex-dependent differences in body mass and composition trajectories during aging. Wheel running (distance, speed, duration) was greater in females than males and declined with age. We conclude that long-term exercise may serve as a preventive measure against age-related weight gain and body composition changes, and that mouse inbred strains can be used to characterize effects of long-term exercise and factors (e.g. sex, age) modulating these effects. These findings will facilitate studies on relationships between exercise and health in aging populations, including genetic predisposition and genotype-by-environment interactions.
衰老与运动量下降以及身体成分的不健康变化有关。运动可改善某些与年龄相关的不良生理变化，并预防多种慢性疾病。尽管有这些益处，但人们的运动意愿以及对运动的生理反应差异很大，而且长期运动及其益处很难在人体中进行测量，成本也很高。此外，人类衰老的生理效应与生活方式和环境的变化相互混淆。我们使用C57BL/6J小鼠在一个严格控制的环境中研究衰老过程中的长期运动模式及其生理效应。将一岁的雄性（n = 30）和雌性（n = 30）小鼠分成大小相等的组群，并再饲养一年。一组小鼠可以使用自愿跑步轮，而另一组除了在笼内活动外没有运动机会。在治疗前、治疗期间和治疗1年后测量体重、身体成分和代谢特征。长期运动显著防止了体重和体脂的增加，同时防止了瘦体重的减少。我们观察到衰老过程中体重和身体成分轨迹存在性别差异。雌性小鼠的跑步距离、速度和持续时间均大于雄性小鼠，且随年龄增长而下降。我们得出结论，长期运动可能是预防与年龄相关的体重增加和身体成分变化的一种措施，并且小鼠近交系可用于表征长期运动的效果以及调节这些效果的因素（如性别、年龄）。这些发现将有助于研究衰老人群中运动与健康之间的关系，包括遗传易感性以及基因与环境的相互作用。
