Riegel Exponent Lookup
The Riegel exponent — also called a fatigue factor, after Peter Riegel, who developed it — is a measure of your fatigue resistance: how much you fade as a race gets longer. It starts to matter at durations beyond about 40–50 minutes; below that, a CP-based plan is the better instrument. This looks up a starting value from a recent race, along with the two neighbouring exponents worth bracketing between.
It is a lookup, not a prediction: it gives you a value to carry into race planning, and never estimates a race power itself.
After any race longer than 10K, work out the exponent your own result implies and record it — that is Palladino’s own advice, and the video under References demonstrates the process. Keep the record by race duration rather than as a single number: your half-marathon exponent is a starting point for a 10K, not the same value. A history of your own eventually replaces this table.
Your recent race
Pick the race you have, the band its finishing time fell in, and the race you are planning.
Riegel exponent
Pick a finishing time above to look up your exponent.
Using the result
- Use a recent race time — within the past year, ideally within the past 3–4 months.
- If you have no recent race, your approximate predicted race time works.
- Results are better when the recent race distance is closer to the target distance.
The table is from the SuperPower Calculator by Coach Steve Palladino. Its underlying population is not published, so treat the exponent as a well-informed starting point rather than a measurement of you — a maximal effort of your own, read off a mean-maximal curve, beats it.
References
- Palladino Power Project
- SuperPower Calculator — copy the workbook
- Calculating Actual Riegel Exponent Post Race using the SuperPower Calculator — measuring your own exponent from a race you have run, rather than looking a starting value up.