Effect of endurance exercise at lactate threshold level on mental and physical health

在这项研究中，我们考察了乳酸阈值(LT)运动(跑步)(LT-RUN)对小鼠和人类身心健康的影响。首先，我们设计了一套用于跑步小鼠呼吸气体交换的测量系统，并对两个广泛使用的小鼠品系C57BL/6J和BALB/c的体能进行了测定，比较了C57BL/6和BALB/c两个品系在体能方面的差异。我们在跑步机上观察到，在LT作用下，海马区5-羟色胺代谢代谢增加。由于应激激素，如糖皮质激素和儿茶酚胺(肾上腺素和去甲肾上腺素)，从乳酸阈值水平开始增加，可以说LT是全身应激反应的阈值。利用小鼠的自愿运动，如果知道这会增加肾上腺对昼夜节律峰值循环ACTH的敏感性，我们探索了可能参与调节肾上腺反应性的分子因素。只有STAR mRNA的表达受到自愿运动的影响，它是线粒体合成胆固醇的关键酶，也受昼夜节律的调节。伴随着肾上腺敏感性的增加，STAR的表达显著增加。我们开发了一种估算LT的方法，以便能够在现场试验中使用。我们发现，用呼吸频率(RF)来检测LT是可行的，可以用100m跑圈的跑速法来估算用呼吸频率代替LT增加呼吸频率的阈值。此外，我们还成功地获得了一个初步数据，表明人类受试者在进行30min的LT训练后，认知能力有所改善。

In this study, we examined the effect of lactate threshold (LT) exercise (running) (LT-run) on mental and physical health using mice and human. First, we designed to develop a measuring system for the respiratory gas exchange of running mice and to determine the physical capacity of two widely used mouse strains, C57BL/6J and BALB/c. The difference in physical capacity was detected between C57BL/6 and BALB/c. The measurement system may be useful in future research regarding genetic contribution to the determination of physical capacity. We investigated a change by a part in a brain of amine under and over LT, increased serotonin metabolic turnover in hippocampus was observed at under LT by a treadmill. Because stress hormones, such as glucocorticoid and catecholamines (adrenaline and noradrenaline), begin to increase from the level over lactate threshold, it may be said LT is the threshold that whole body stress response. Using voluntary exercise of mice, which if known to increase the adrenal sensitivity to circulating ACTH at the circadian peak, we explored molecular factor that may be involved in regulating the responsiveness of the adrenal gland. Only the StAR mRNA expression, which is a key enzyme for cholesterol synthesis in mitochondria, and also regulated by circadian rhythm, was altered in response to voluntary exercise. The StAR expression increased significantly, concomitantly with the increased adrenal sensitivity. We developed a method estimating LT to be able to use in field test. We found that the use of respiration frequency (RF) for the detection of LT is available for the estimation of a threshold to increase RF in place of LT by running speed increasing method using 100m running circle. More over, we are succeeded in getting a preliminary data suggesting an improvement of cognition after LT running for 30 min for human subjects.