In running, a split refers to the time it takes to complete a specific distance or section of a course. For example, if youre running a 5K, you could break the run up into mile- or kilometer-long splits. Runners use splits to track their pace and see if theyre keeping up the right speed. By keeping an eye on split times, runners can see how theyre pacing and even see how it improves over time. Split times can also reveal areas for improvement, such as sprinting too fast at the beginning of a run. Negative splits happen when a runner speeds up in the second half of a race and achieves a shorter mile split. This is a strategy that can improve performance during races and help build endurance. Splits can be measured in miles, kilometers, or any other unit of distance. Runners can use GPS watches or running apps to track their splits.