게 뛰어놀다

run around playing, happily etc.

뛰어놀다 is running around at play — children outdoors, a crowd at a concert — and the -게 adverb says in what spirit. In these lines the adverb is almost always about high energy or freedom: 신나게 'excitedly' appears three times, alongside 밝게, 땀나게, 자유롭게 and 힘차게. The word is warm and positive; it is not a neutral term for exercise.