The phrase "stepped-up" refers to an increase in intensity or effort. Synonyms could include heightened, escalated, intensified, elevated, raised, amplified, or boosted. These words convey a sense of something being taken to the next level, whether it's in terms of productivity, performance, or effectiveness. Other alternatives might include phrases such as "upped the ante" or "cranked up the volume." Each of these synonyms can be used to describe a situation where someone has taken things to the next level, showing greater focus, determination, and energy in their approach. By using these words, you can convey a sense of urgency and commitment in your writing that will engage and inspire your readers.