Early. Took a yoga class and hit the sack.

他们觉得是怎么回事。

I'm so tired that I think I'll just hit the sack.

我好累，所以我想干脆去睡觉。

And in others, kids can never study or even watch TV once Dad hits the sack.

也有些情形是只要老爸一睡觉，孩子们可能就无法读书或看电视。

If you hit the sack or hit the hay you are officially going to bed for the night.

如果你“hit the sack/hay（睡觉）”代表你是正式要上床睡觉了。

It sounds like they are tried and ready to sleep. That's what hit the sack means; you are going to bed.

听起来他们很累，准备去睡觉。“hit the sack”的意思是：你要去睡觉了。

Oh, well. I guess I'll hit the sack.

哦, 好的. 我想去睡觉了。

It’s one o'clock – time to hit the sack.

【sack】现在是一点钟，该睡觉了。

I took your college course. I say it's time to hit the sack.

我听完课了 我们准备走吧。

Former British Prime Minister Margaret Thatcher famously claimed that she only hit the sack for five hours a night.

英国前首相玛格丽特·撒切尔 (Margaret Thatcher) 曾说过，她每晚只睡五个小时。

Starting at least an hour before you hit the sack, cut back on how much exposure to bright light you're getting, Experts advise.

专家建议，至少从睡觉前1小时开始，降低暴露在强光下的时间。