The phrase "breaks one's neck" typically refers to a situation where someone faces extreme danger or puts in intense effort to achieve something. Antonyms for this phrase would be more along the lines of taking it easy or exerting minimal effort. Some possible antonyms might include "relaxing," "resting," "taking it slow," "slacking off," or "coasting." These words suggest a lack of urgency or danger, and a relaxed attitude towards achieving goals. While breaking one's neck may be admirable in some situations, it is important to recognize the value of rest and balance in our lives.