This is the 18524th most frequent Korean word.
시작해서
"Starting from" or "having started."
In this sentence, '시작해서' is used to describe the initiation of an activity (morning exercise) that leads to the described result (energetic day).
그는 아침 운동을 시작해서 하루를 활기차게 보냅니다.
He starts his day energetic by beginning morning exercises.
Here, '시작해서' connects the beginning of watching a movie with the duration of the night spent watching it.
영화를 시작해서 밤늦게까지 봤어요.
We started watching the movie and continued late into the night.
In this example, '시작해서' links the commencement of the meeting to the subsequent discussion of important topics.