This is the 13442nd most frequent Korean word.
뛰면서
"While running"
뛰면서 is acting as an adverbial clause indicating the simultaneous action of running while exercising.
그는 아침에 공원을 뛰면서 운동을 합니다.
He exercises in the morning by running in the park.
뛰면서 indicates the act of thinking occurring simultaneous to running, showing multitasking or concurrent activities.
새로운 아이디어를 찾으려고 공원을 뛰면서 생각했습니다.
I thought while running in the park to find new ideas.
뛰면서 emphasizes that the action of talking is taking place during the act of running, implying coordination of two actions.