Antonyms for the phrase "lives it up" typically include terms which suggest a more modest or restrained lifestyle. Such words might include "lives humbly," "lives simply," or "lives frugally." Alternatively, antonyms may reflect a different attitude or approach to life altogether, such as "lives conservatively," "lives cautiously," or "lives modestly." Depending on the context, antonyms could also include phrases which suggest a negative or self-destructive lifestyle, such as "lives recklessly," "lives carelessly," or "lives dangerously." Ultimately, the most suitable antonym for "lives it up" will depend on the intended meaning and context of the phrase.