If you don't consume enough water, your kidneys suffer, causing symptoms such as headaches, tiredness and loss of concentration.

如果没有喝下足够的水，肾脏就会受损，引起头痛，疲劳，注意力不集中的症状。

Of course, the 4 hrs group performs the worst, but these results don't just show a loss of concentration, they show full lapses in awareness called microsleeps.

当然，4 小时组的表现最差，但这些结果不仅显示注意力不集中，还显示了被称为微睡眠的意识完全丧失。