What Is a Negative Split?

runners in race
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"I've heard runners talk about how they ran a negative split for a marathon. What does that mean? What are the advantages and disadvantages?"

The term "negative splitting" refers to running the second half of a race faster than the first half. It is a pacing tactic for running as well as for other sports such as swimming. You can do negative splits for any distance of race, from 5K up through marathons, and use it for training runs as well.

For instance, if you're running a marathon and you run the first 13.1 miles in 2:01:46, and then run the second 13.1 miles in 1:59:30, you ran a negative split.

Negative splitting is often called the ideal way to run a long distance race such as a half or full marathon. Many runners do the opposite by going out too fast in the beginning, and then slowing down significantly in the second half of the race. It's a common mistake because you feel rested and strong in the beginning, so it's tempting to go out fast. It takes a lot of discipline and practice to achieve a negative split. Most people can't do it in their first marathon. But, generally, if you can hold back and conserve your energy in the first half of the race so that you can run faster in the second half, you'll perform much better overall.

Positives of Negative Splits

An easier pace at the beginning of the race gives your muscles more time to warm up.

Running a negative split also decreases your risk of hitting the wall in the late miles of a half or full marathon. In addition, running faster and stronger in the second half of the race is a much more enjoyable experience than crashing and slogging through the final miles.

Negatives of Negative Splits

The best-laid plans of runners often go awry.

You need to be able to accurately stay on pace in order to even attempt negative splits. You should use a timing app or Garmin to ensure you are on the pace you are aiming for.

Running a little bit slower early in a long distance race can be difficult because you'll feel full of energy and you may feel frustrated that other runners are passing you. Running a negative split half or full marathon require a lot of patience and can be a difficult mental challenge to pull off.

While you may have held back for the first half of the course, you may discover that wind, heat, dehydration, hills, runner's trots or other factors are rearing their ugly heads on the back of the course. Now you can't speed up to your intended negative split pace.

Practice Negative Splits

If you plan to use a negative split pacing strategy on race day, practice it in your training runs. Aim to finish some of your long runs by picking up the pace for the second half of your run. You can use the strategy with some of your shorter runs, too.

Once a week, do one of your shorter runs at easy pace for the first half and pick it up to your intended marathon pace for the second half.

Also see:


Santos-Lozano A, Collado PS, Foster C, Lucia A, Garatachea N. Influence of sex and level on marathon pacing strategy. Insights from the New York City race. Int J Sports Med. 2014 Oct;35(11):933-8. doi: 10.1055/s-0034-1367048.

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