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RiverMathRiverMath

Race predictor

Uses Peter Riegel’s formula, where time scales with distance to the power of 1.06 assuming appropriate endurance training. A 10 km result provides a much more reliable baseline for a marathon than a short 5 km time trial.

5 km · 4:48 / km
23:59
10 km · 5:00 / km
50:00
Half marathon · 5:14 / km
1:50:19
Marathon · 5:27 / km
3:50:01

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