When we do the same movements with our bodies over and over again, we overuse some muscles and that overuse can lead to strain and injury.
当我们的身体一遍又一遍地做同样的动作时，会过度使用一些肌肉，从而导致劳损和受伤。
2
We also know that a long time without change or challenge can lead to boredom, and physical and mental strain.
我们也知道，长时间没有变化或缺乏挑战会导致无聊，造成身体和心理上的疲惫。
3
Like a computer the brain works best when it is cool, but putting too great a strain on it can lead to overheating which reduces its ability to process information.