Altigraph · Pace plan
Your pace on every kilometre, adjusted for the hills.
Drop the course of your race (GPX, FIT, TCX) or paste its public Strava route, enter the time you are aiming for or your pace on the flat: you get the pace to hold on each kilometre according to its gradient, the split times, a table to print and an image to keep on your phone.
Drop a GPX, FIT or TCX file here
Read inside your browser. Nothing is uploaded.Or pick a race from the race profiles: every page has a "pace plan" button.
The plan, kilometre by kilometre
Even effort: slower on the climbs, a little faster on the descents. Print it, or keep the image on your phone.
| Km | Gradient | D+ / D- | Pace | Split | Elapsed |
|---|
How the pace is adjusted, and what the model does not know
The model: same effort on every kilometre
The plan assumes you spend the same effort on every metre: slower uphill, a bit faster downhill, so that the whole race costs what a flat race of your target time would. Uphill, the extra cost of each gradient is taken from the laboratory measurements of Minetti and colleagues (Energy cost of walking and running at extreme uphill and downhill slopes, Journal of Applied Physiology, 2002): running at 5 % costs about 30 % more energy per metre than on the flat, at 10 % about 65 % more. Downhill, energy is not the limit, braking and impact are: Strava's grade adjusted pace model, fitted on millions of real runs, finds that no descent is worth more than about 12 % of pace (the best case is around -9 %) and that by -18 % a descent is no faster than the flat. The plan uses that curve for descents.
What it does not know
The terrain (mud, rocks, stairs and single track slow a trail far more than the gradient does), the fatigue of a long race (the last kilometres are slower than the model says, whatever the profile), the heat, the altitude, the wind, the crowd at the start, and your own strengths: some people descend well, others climb. Above about 15 % the model keeps a running effort while most runners walk, which is usually the faster choice there. Read the plan as a shape, not as a contract: the kilometres that must be slower, the ones where time is gained.
Where the course comes from
From the file you drop (read in your browser, nothing uploaded) or from the public Strava route you paste, read without an account through its public embed. The gradient of each kilometre is computed after smoothing the altitude over 50 m, like on the home page, so the profile is the same one you see there.
Sources
Minetti A. E., Moia C., Roi G. S., Susta D., Ferretti G., Energy cost of walking and running at extreme uphill and downhill slopes, J Appl Physiol 93:1039-1046, 2002: https://journals.physiology.org/doi/full/10.1152/japplphysiol.01177.2001. Strava Engineering, An Improved GAP Model, 3 October 2017: https://medium.com/strava-engineering/an-improved-gap-model-8b07ae8886c3 (minimum pace factor 0.88 at -9 %, back to 1.0 at -18 %).