I need to catch up on some sleep.
→(미뤘던)잠을 좀 자야겠어.

※catch up to ~을 따라잡다.

〔예문〕
You should study hard to catch up with others.
다른애들을 쫓아가려면 너는 열심히 공부해야해.

You go on, I will catch up to (with) you later.
너 먼저가, 내가 뒤따라 갈께.

I need to catch up on some sleep this weekend.
나는 이번주말에 미뤘던 잠을 좀 자야겠어.