What do the hills cost?
Pick your race or describe the course to see your finish and your pace on the climbs, or convert any pace with the Grade-Adjusted Pace (GAP) calculator.
A recent race in good weather. Aiming for a goal instead? The last line of the answer covers it.
Each is a climb per mile scaled to the marathon, priced the way real mapped courses that climb that much price.
| 6% up | 12:16/mi | +3:18/mi |
|---|---|---|
| 4% up | 11:05/mi | +2:07/mi |
| 2% up | 9:59/mi | +1:01/mi |
| Flat | 8:58/mi | flat pace |
| 2% down | 8:32/mi | −26 sec/mi |
| 4% down | 8:13/mi | −45 sec/mi |
A 2% grade rises about 106 ft per mile. Most road climbs are 2 to 4%; a bridge or a short steep hill can reach 6%.
How we got this
Every slope is priced with one curve. Climbing costs what lab measurements of uphill running show, about 5.5% more time per 1% of grade near flat. Descending gives back less, damped to what real race results show, and the credit stops on descents steeper than about 18%. That's why a course that climbs and drops the same amount still runs a little slower than a flat one.
Each choice is priced the way real mapped courses that climb that much per mile price, a mile at a time, so it matches what a race page shows for a typical course of that kind. Rises that climb and drop inside a mile cost little, which is why it's lower than the same climb typed as totals. One race can still differ: long climbs cost more than the same climbing in short rollers. Load the race itself for its exact figure.
Questions
- What is grade-adjusted pace (GAP)?
- The pace on flat ground that takes the same effort as your pace on a hill. 10:00 per mile up a 6% grade is about 7:18 per mile on the flat, and an 8:00 per mile flat pace is about 10:57 per mile up the same grade. Pick Grade-adjusted pace above to convert either way, in minutes per mile or per kilometer.
- How much slower should I run up a hill?
- Near flat, each 1% of grade costs about 5.5% at the same effort, more on steep climbs. A runner averaging 9:00 per mile (5:36 per km) runs about 11:08 per mile (6:55 per km) up a 4% grade and about 8:15 per mile (5:08 per km) down one. Run the climbs by effort, not by pace: holding your flat pace uphill spends energy you need later.
- How much do downhills give back?
- Less than the climbs cost. A 2% descent is worth about 5% faster, the most is about 12% faster near a 9% descent, and past about 18% we give no credit at all, because braking takes the gain back. That is why a course that climbs and drops the same amount still runs a little slower than a flat one. The downhill side is damped to what real race results show.
- Why does Boston show next to no effect?
- Boston climbs about 720 ft (220 m) and drops about 1,190 ft (360 m) on its mapped course. Over the whole race the descents give back about what the Newton hills cost, so the hills change how the race feels and where it hurts more than the finish time. The long early descent also pounds the quads, so the downhill credit assumes legs trained for it.
- What do flat, rolling and hilly mean?
- By the climb per mile: flat is about 8 ft per mile (1.5 m per km) like Chicago, rolling about 26 ft (4.9 m per km) like Marine Corps, hilly about 47 ft (8.9 m per km) like San Francisco, very hilly about 70 ft (13 m per km), and mountain or trail about 140 ft (27 m per km), like a hilly trail marathon. Each choice shows the climb and descent it means over your distance, and is priced the way real mapped courses with that much climbing per mile price on their race pages: next to nothing for flat, then about 0.6%, 1.3%, 2.1% and 6.1% slower.
- Why does loading a race give a different answer than its climb and descent?
- Totals can't tell one long climb from short rises that cancel within a mile. A loaded race's mapped course is priced a mile at a time, each mile at its own slope, which is the number its race page shows. The flat, rolling and hilly choices are priced the way real mapped courses with that climb per mile price. Climb and descent you type use a simpler totals model, which spreads them as if every rise were the same size, so they read a little higher. One course can still differ from the choice that matches its climb: long climbs cost more than the same climbing in short rollers.