| What it is | 2nd half faster than the 1st |
| Strategy | Start conservative, finish strong |
| Avoids | Going out too hard and fading |
| On trails | Judge by effort, not exact pace |
A negative split is completing the second half of a run or race faster than the first half. Considered an efficient, disciplined pacing strategy, it relies on starting conservatively to conserve energy and finishing strong, avoiding the early-pace blowups that lead to fading. On trails, where terrain varies, it’s judged by effort rather than exact pace splits.
Pace smart
A strategy to avoid the bonk, drawing on the sustainable pace built by tempo runs and long runs.
Frequently asked questions
What is a negative split?
A negative split means running the second half of a race or run faster than the first half. It's the opposite of a positive split (slowing down), and it reflects disciplined pacing — holding back early to conserve energy, then speeding up when others are tiring, often producing strong finishes and better overall times.
Why are negative splits a good strategy?
Because starting too fast depletes energy and causes fading or blowups late in a race, while a controlled early pace preserves fuel and form so you can finish strong. Negative splitting harnesses this, reducing the risk of hitting the wall and often leading to faster, more comfortable races, especially over longer distances.
How do you run a negative split on trails?
Since trail terrain makes even pacing impossible, aim for an even or slightly building effort rather than even pace: start conservatively, fuel and hydrate well, and have enough left to push the runnable sections in the second half. On hilly courses, judge by perceived effort and heart rate, accepting that pace will swing with the terrain.
Sources
- Race pacing — American Council on Exercise
- Pacing strategy — American Trail Running Association