今朝起きた時、体がとても軽かったです。 I felt refreshed when I got up in this morning.

昨夜、夜10時に寝たら今朝起きた時、体がとても軽かったです。

睡眠時間も重要ですが、寝る時間帯もやっぱり大事ですね。

I felt very refreshed when I got up in this morning because I went to bed at 10 pm last night.

I came to realize that the time of going to bed is the bottom line as well as sleeping hours.