How to pace downhills in a road race
Run a descent quicker than your average, by about 5% for each 1% of downhill grade, and no more. The time on offer is smaller than it feels: a 3% descent gives back 15%, while the same climb costs 17%. Push harder than that and you pay for it later.
Updated
How much quicker to run downhill
At the same effort as your flat pace, each downhill grade is worth this much. The numbers come from the same cost-of-running curve as every gpx2pace plan.
| Downhill | Time saved | 5:00/km becomes | 8:00/mi becomes |
|---|---|---|---|
| −1% | 5.3% | 4:44 | 7:35 |
| −2% | 10.3% | 4:29 | 7:11 |
| −3% | 15.1% | 4:15 | 6:48 |
| −4% | 19.5% | 4:01 | 6:26 |
| −5% | 23.7% | 3:49 | 6:06 |
| −6% | 27.6% | 3:37 | 5:47 |
The steepest descents on real courses
The steepest sustained drop on each course page, with the quickest target the plan sets on it at a 3:30 goal. Road marathon descents are mostly gentle. Targets are set per whole kilometre, so a short steep drop inside a flatter kilometre earns less than its gradient suggests.
| Course | Where | Drop | Target vs average /km |
|---|---|---|---|
| Boston Marathon | km 0.0 to 0.8 | −37 m at 4.3% | 4:09 vs 4:59 |
| California International Marathon | km 17.0 to 17.8 | −23 m at 2.9% | 4:31 vs 4:59 |
| London Marathon | km 2.3 to 5.3 | −44 m at 1.5% | 4:17 vs 4:59 |
| Berlin Marathon | km 27.8 to 30.0 | −10 m at 0.4% | 4:49 vs 4:59 |
| Rotterdam Marathon | km 3.0 to 10.0 | −8 m at 0.1% | 4:50 vs 4:59 |
Why descents are a trap
Downhill running feels easy on the lungs, so it is tempting to let the pace run away and bank time. Two things make that a poor trade. First, the saving is smaller than the cost of the same climb, so time banked downhill does not cover time lost on the next hill. Second, running downhill loads your thigh muscles as they lengthen to brake each stride, and that kind of work causes more muscle soreness and damage than flat running. A fast early descent can show up as heavy legs 25 km later.
Courses that start downhill make this worse, because your legs are fresh and the crowd is fast. Boston and the California International Marathon both start downhill; the plan already gives you quicker splits there, so match them rather than beat them.
Running them on the day
- Let gravity set the pace, not effort. Keep breathing at the same level as on the flat; the pace will rise on its own.
- Check the band at the bottom, not halfway. A descent split is short, and instant pace on a watch overreacts. The cumulative time at the next marker tells you if you are on plan.
- Steep and twisting means slower than the table. The numbers assume you can run freely. On tight corners or a steep ramp, footing comes first.
See the downhill splits for your own course.
Plan my race from a GPXPacing guidance only, not medical advice. Adjust for heat, wind and how you feel on the day.