Riegel’s formula is a mathematical equation used to predict race times for runners. It was first published by Pete Riegel, an American research engineer in 1977.
The formula takes into account a runner’s recent race time and distance to then estimate the time to complete an upcoming race:
T2 = T1 x (D2 / D1) ^ 1.06
- D1 = Previous race distance
- D2 = Upcoming race distance
- T1 = Previous race time
- T2 = Prediction of race time for upcoming race
Overall, the evidence suggests that Riegel’s formula is a useful tool for predicting race times in runners, but it should not be relied upon as the sole means of determining race performance. Other factors such as recent training history and specificity should also be taken into account when predicting race times.
Despite its limitations, Riegel’s formula continues to be widely used by runners, coaches, and exercise physiologists to help predict race times and track performance improvements.