The phrase "got second wind" refers to the feeling of renewed energy or vigor after feeling exhausted or worn out. Its antonyms could include phrases like "ran out of steam," "hit the wall," "wore down," or "lost momentum." These phrases all convey a sense of tiredness, fatigue, or lack of energy. Other antonyms might include phrases like "never lost steam," "pressed on," "kept going," or "ran with the wind." These phrases suggest an unbroken, persistent determination or tenacity, reinforcing the idea that "getting a second wind" is a powerful and transformative experience.