462 –Why “sleeping in” on weekends isn’t good for teens 2

Source: 

https://www.health.harvard.edu/blog/why-sleeping-in-on-weekends-isnt-good-for-teens-201301115763

3. Sleeping late on Saturday and Sunday may fill that deficit, but it creates a bigger problem. It allows your teen’s inner clock to further drift away from the external clock, worsening the shift begun by delaying bedtime on school nights. The result: the circadian sleep is thrown out of whack, which makes it much more difficult to get up at the usual wake time.

Drift away: 渐渐远离

Circadian: 昼夜的

Thrown out of whack: 被打乱 （whack: 不正常）

周六和周日晚睡可能会弥补这一不足，但它带来了一个更大的问题。这会让你孩子的内部生物钟与外部生物钟进一步偏离，让他们在上学的晚上推迟就寝时间，从而加剧了这种转变。结果就是:昼夜节律睡眠被打乱，使人们更难在正常的起床时间起床。

In effect, by sleeping late on Saturday and Sunday, your teen is suffering from the equivalent of a five-hour jet lag when it’s time to get up on Monday morning. The alarm clock may be saying 6:00 am, but his or her inner clock is reading 1:00 am. This will make it much harder for your teen to concentrate and take in anything at school. When this becomes a regular pattern, it can also have a significant effect on mood.

Jet lag: 时差

Take in：吸收、接受

实际上，如果你的孩子在周六和周日睡得晚，那么你的孩子在承受的痛苦相当于周一早上起床时倒了5个小时的时差。闹钟可能显示的是早上6点，但Ta的内在时钟显示的是凌晨1点。这将使你的孩子很难集中注意力，在学校无法接受任何东西。当这成为一种规律模式时，它也会对情绪产生重大影响。