Peter Riegel

Peter Riegel (January 30, 1935 – May 28, 2018) was an American research engineer who developed a mathematical formula for predicting race times for runners and other athletes given a certain performance at another distance. The formula has been widely adopted on account of its simplicity and predictive accuracy.

Life and career Riegel earned a BS in mechanical engineering from Purdue University in 1959 and his master's degree from Villanova University in 1966. and another for an exhaust regulator valve for a push-pull diving system.

Race time prediction In a 1977 article for Runner's World Magazine, Riegel proposed a simple formula for comparing relative performances at different distances. The formula is most commonly quoted as: where:

is the time achieved for is the time predicted for is the distance over which the initial time is achieved is the distance for which the time is to be predicted

Riegel expanded on his thesis in a 1981 article for American Scientist, stating that the formula concerns activities in the "endurance range", namely lasting between 3.5 and 230 minutes. The analysis deals with running, swimming and walking.

The simplicity of the formula and its predictive accuracy has resulted in it being adopted widely by websites such as Runner's World. Some sites have modified it, stating that the value of 1.06 given for the exponent b in the formula results in seemingly unachievable predictions for longer distances.

Publications

Death Riegel died in Columbus on May 28, 2018, at the age of 83.