AIMS The objective of this study was to establish a more accurate analytical model and method for grip strength test of mice and to investigate the beneficial effects of lifelong exercise training to prevent functional decline of muscle during aging. MAIN METHODS Fifty randomly selected adult male BALB/c mice (24-56 week age) were used in grip strength testing periodically with short periods (3 s). Such method was used to detect a modified grip strength test. Then sixty-four male BALB/c mice (6 week age) were assigned into groups Sedentary (n = 32), Exercise (n = 32, lifelong treadmill training 3 days per week and 30 min per day). The muscle strength and morphology parameters were measured at the ages of 6, 12, 30 and 64 weeks, respectively. KEY FINDINGS The grip strength (peak value and endurance) of sedentary group monotonically decreased in adult BALB/c mice during aging, while that of exercise group remained a relatively high level even slightly increased at aged period. Meanwhile, lifelong exercise training could slow down the loss of gastrocnemius muscle mass, myofiber cross-sectional area, myonuclear number and myonuclear domain. The number of myofibers was relatively stable in adult mice. SIGNIFICANCE Modified analytical method for grip strength testing, with improved accuracy and reliability, may be an efficient substitute for conventional method in measuring the strength and endurance of mice and investigating the effect of lifelong exercise on muscle loss. Lifelong exercise training helps prevent muscle loss and muscle defunctionalization while aging.

中文翻译：

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在BALB / c小鼠的衰老过程中，终身跑步机训练可改善通过改良握力测试检测到的肌肉功能。

目的本研究的目的是建立一种更准确的小鼠握力测试模型和方法，并研究终生运动训练对防止衰老过程中肌肉功能下降的有益作用。主要方法50只随机选择的成年雄性BALB / c小鼠（24-56周龄）在短时间内（3 s）定期进行抓地力测试。这种方法用于检测改进的抓地力测试。然后将64只雄性BALB / c小鼠（6周龄）分为久坐（n = 32），运动（n = 32，每周3天，每天30分钟的终身跑步机训练）组。分别在6、12、30和64周龄时测量肌肉力量和形态参数。主要发现成年BALB / c小鼠的久坐组的握力（峰值和耐力）在衰老过程中单调下降，而运动组则保持较高水平，甚至在衰老期略有增加。同时，终生运动训练可以减慢腓肠肌肌肉，肌纤维横截面积，肌核数目和肌核区域的损失。成年小鼠的肌纤维数量相对稳定。意义改良的握力强度测试分析方法具有更高的准确性和可靠性，可以有效地替代传统方法来测量小鼠的力量和耐力，并研究终身锻炼对肌肉损失的影响。终身运动训练有助于防止衰老时的肌肉丢失和肌肉失功能。