alligator running

Equivalent Running Performances

This form tells you what running times you should expect on different distances if you were to train specifically for those distances. The assumption is that your speed as a fraction of the world record is a constant that is the same for every distance.

Distance you ran:

Time you took: h m s



Your speed as a fraction of the world record:

Equivalent performances:


About the world records method

A simple formula to predict performance is t2 = t1 × (d2 / d1)b where b can depend on the distance or other factors. Peter Riegel proposed using the constant b=1.06. The graph below derives b experimentally using world records. The peak between 400m and 800m is explained by the transition from sprint to middle-distance which requires the runner to tap from a different energy source. Smaller features in the graph might be noise that could be smoothed out. It's also not clear if the curve obtained from world records applies to amateurs without any change. Nevertheless, the method is reasonable and easy to understand.

Exponent vs Distance graph

Some of the many other race performance predictors

Comparing multiple formulas:

Using the VO2 max formula:

Using Riegel's formula t2 = t1 × (d2 / d1)1.06:


Page created: June 11, 2016
Page last updated: October 9, 2020