The term "trails behind" means to follow or lag behind someone or something. Hence, the antonyms for this phrase will be the words that denote the opposite direction, i.e., to lead or be ahead of something or someone. Some antonyms for "trails behind" are: "leads the way," "takes charge," "sets the pace," "forges ahead," "surges forward," "takes the lead," "advances," "heads up," "guides," and "pioneers." These words can replace the phrase "trails behind" in a sentence and transform its meaning to reflect the opposite context, which is to be in charge, lead or ahead of something or someone.