There are numerous synonyms for the phrase "run fast" that can come in handy while expressing speed in different ways. Some of the most common ones include sprint, dash, rush, bolt, dart, gallop, hasten, speed, whip, blaze, charge, hustle, jog, and zoom. While "run fast" simply implies a quicker pace than usual, each of these synonyms have their own connotations attached to them that can make the language more descriptive and interesting. For instance, sprint and dash are often used to indicate short bursts of speed, while gallop and hasten tend to suggest a more continuous, determined effort. Choosing the right synonym can also help vary the sentence structure and add more impact to your writing.