The antonyms for the phrase "most speeded up" can be quite varied, depending on the context in which the phrase is used. Some antonyms might include phrases like "slowed down," "paced out," "decelerated," "relaxed," or "reduced speed." Each of these phrases carries a slightly different connotation, and might be used in different ways depending on the situation. For example, if someone is trying to complete a project quickly, they might say that they need to "speed things up." If they are feeling overwhelmed or stressed, however, they might say that they need to "slow things down" in order to avoid burnout. In any case, antonyms for "most speeded up" are useful for communicating a sense of balance and control, even in high-pressure situations.