Laps and splits take the guesswork out of timing your workouts and pacing your races.  A lap is simply the time it takes to complete an individual segment of your workout. A split is the cumulative elapsed time of those lap segments, from the start of the workout.  The main advantage of the lap and split data is that it helps you understand your performance improvements. If you are training, you can use it to see how you’re performing between different marker points of your workout; over time, you can evaluate your training progress for the same course, from session to session. If you are racing, throughout the course of a race event, the lap and split data will give you real-time feedback to adjust your current pace and meet your ultimate finish-line time goals.