Anytime you enter into a competitive, long-distance race, you’re going to need a strategy. Whether you’re a seasoned pro looking to win a medal or just a beginner who simply wants to complete a marathon for the first time, it’s critical to learn how to pace yourself, measure your performance throughout the race, and apply these stats to how you plan to run. This may all seem difficult to apply at first, but soon you’ll find measuring your pace per set distance throughout your run to be extremely helpful to your overall performance.

This is where a Split Calculator comes into play. This is not to be confused with splitting up a training run so you can get 5 miles in before and after work to add up to 10 miles in a day. Running Splits is a technique used by experienced long-distance runners to measure their pace at set distance markers throughout their race. Let’s say you’re going to be running a 5 mile race aiming for a finish time of 40 minutes. By using our Split Calculator below, enter the distance of the race and the estimated time to complete it. Make your timed markers, or “Splits”, at 1 mile each. The calculator should show you around what time you should be passing each mile marker- about 8 minutes per.

So how does this help you as a runner? By noting your times as you pass a distance marker, you’ll get a better gauge of your pace throughout the race. If you pass your second mile split at around 14 minutes, you’re running too fast. Probably you should slow down a bit as to not burn out too quickly. On the other hand, if you’re hitting 2 miles at 17 minutes, you’ll need to run a little faster.

These measurements become extremely helpful during even more long-distance runs like marathons. In the past, experienced runners might write their estimated splits on their forearms with a permanent marker, now they’re usually doing it with apps or fitness trackers. The concept is still the same.

Calculating your splits can of course also be used during your training when preparing for a long race. By measuring how you’re performing at each distance marker over time, you can see where your energy is starting to flag and where room for improvement can be made.

To get into even deeper racing strategy, it’s important to cover the concept of Negative Splits. Many runners like to hold back their pace during the first half of a long event. Then in the second half, they add some fuel to their fire and start running faster. The idea is much like putting energy in the bank- it’ll pay off later down the road. Running at a slower pace than you are capable of is called running in a Negative Split. Conversely, running faster than your set distance markers is called a Positive Split.

Some long-distance runners swear by this technique, but for others, it’s debatable whether running in a Negative Split helps win a race. In any case, it’s worth it to know your split times and at least experiment with running in a Negative Split during training and see how your ultimate finish time is compared to simply running at an even pace throughout the run.