Viidik A, Skalicky M
Institute of Anatomy, University of Aarhus, Denmark.
Aging (Milano). 1997 Feb-Apr;9(1-2):64-72. doi: 10.1007/BF03340129.
It has been shown that life-long, regular physical exercise has benefits for humans as well as laboratory animals. Population studies have shown that the longevity of humans is increased due to the decrease in all-cause mortality. Further, the functional capacities of organ systems, especially the cardiovascular, are maintained better. Body fat content stays lower. Similar conclusions have been drawn from animal studies, most of them using voluntary exercise in running wheels. We have previously shown that spontaneous activity, measured in an open field setting, is better preserved, suggesting a slowing of sensorimotor impairment with age, and possibly improved maintenance of dopaminergic and cholinergic systems. Further, the systemic effect on connective tissues was a slowing of the age-dependent increase of stability by changes in the cross-linking patterns. The purpose of the present investigation was to analyze whether late-onset training programs had any such effects, i.e., whether the aging effects seen in sedentary animals could be reversed to some extent. We trained male Sprague-Dawley rats from the age of 18 and 20 months until the age of 22 months, i.e., for 4 and 2 months, in a treadmill for 800 m/day. Spontaneous activity in an open field was assessed at the ages of 18, 20, and 22 months. For systemic changes in connective tissues, tail tendons were analyzed with respect to thermal stability and biomechanical strength parameters. The rats trained for 4 months lost weight significantly, which suggests that most of the fat accumulated during a sedentary life can be removed by physical exercise. Two months of training, either from the age of 18 or 20 months, had a positive effect on spontaneous activity, while the last 2 months of a 4-month training period had a negative influence. We conclude that the exercise program was too strenuous to be maintained for 4 months, which should be interpreted as a failure to increase the functional capacity sufficiently. Analysis of the thermal stability and biomechanical properties showed that both training programs moved these properties in a "younger" direction. We conclude that training starting late in life also influences the aging rat in a positive way, although there are limitations to the intensity of training that is beneficial.
研究表明，终身规律的体育锻炼对人类和实验动物都有益处。人群研究表明，全因死亡率降低，人类的寿命得以延长。此外，器官系统的功能能力，尤其是心血管系统，能得到更好的维持。身体脂肪含量保持在较低水平。动物研究也得出了类似的结论，其中大多数是利用动物在跑轮上的自主运动。我们之前已经表明，在旷场环境中测量的自发活动能得到更好的保持，这表明随着年龄增长感觉运动障碍有所减缓，并且多巴胺能和胆碱能系统的维持可能得到改善。此外，对结缔组织的全身影响是通过交联模式的变化减缓了与年龄相关的稳定性增加。本研究的目的是分析晚期训练计划是否有此类效果，即久坐不动的动物中出现的衰老效应是否能在一定程度上得到逆转。我们从18个月和20个月大开始，对雄性斯普拉格 - 道利大鼠进行训练，直到22个月大，即分别训练4个月和2个月，在跑步机上每天跑800米。在18、20和22个月大时评估旷场中的自发活动。对于结缔组织的全身变化，对尾腱的热稳定性和生物力学强度参数进行了分析。训练4个月的大鼠体重显著减轻，这表明久坐生活中积累的大部分脂肪可以通过体育锻炼去除。从18个月或20个月开始的两个月训练对自发活动有积极影响，而4个月训练期的最后两个月有负面影响。我们得出结论，该运动计划过于剧烈，无法维持4个月，这应被解释为未能充分提高功能能力。对热稳定性和生物力学特性的分析表明，两个训练计划都使这些特性朝着“更年轻”的方向发展。我们得出结论，晚年开始训练也会对衰老的大鼠产生积极影响，尽管有益训练的强度存在局限性。
