The phrase "sit on one's butt" implies laziness and inactivity. Its antonyms, on the other hand, connote energy, movement, and productivity. Some suitable antonyms for the phrase include "be active," "get moving," "stay engaged," "work diligently," "be productive," and "get things done." These phrases depict the opposite of sitting idle, and instead reflect a lifestyle of constant motion and accomplishment. In conclusion, the antonyms of "sit on one's butt" promote an active and vibrant lifestyle that fosters growth, development, and fulfillment.