Downhill Pace Adjustment Calculator

How it is calculated

The tool multiplies your flat pace by a factor fitted to real downhill running, where x is the steepness of the descent in percent (a positive number): factor = 1 − 0.020 × x + 0.001 × x². The factor is lowest near 10 % grade (0.90, about 10 % faster for the same effort), is back at 1.00 around 20 %, and goes above 1 beyond that, because braking and eccentric muscle loading cancel the benefit. Adjusted pace is flat pace × factor in min/km. Descent time is adjusted pace × distance (km), and time saved is the difference from holding flat pace; on very steep grades it comes out negative, meaning time lost. Flat pace goes in as minutes and seconds in separate boxes (seconds below 60, total pace not faster than 1:30 /km), grade may be 0 to 30 %, distance must be above zero. Values outside these limits show no result. The factor is held to at least 0.5 and the adjusted pace to 0:30 /km at the fastest.

Common mistakes

• Entering the downhill pace you actually ran as the flat pace. The input must be your flat-ground effort pace; otherwise the adjustment is applied on top of a pace already helped by the slope.
• Typing 90 or more in the seconds box, or a pace such as 5:90. The seconds box must be below 60, and an invalid value gives no result.
• Entering the grade as a negative number for a descent. The field takes steepness as a positive percent; −8 gives no result, as does anything above 30.
• Assuming steeper always means faster. The benefit peaks near 10 % and by about 20 % it is gone, because braking costs time.
• Using the saved time as a target. It is a modelled estimate for equal effort, and on technical trails or after long climbs your legs may not allow it.