Why is the exponent 1.06 in Riegel's formula?

Peter Riegel analyzed thousands of running, swimming, and cycling world records and found that human speed degrades at a regular power law rate with an exponent of 1.06 across distances.

Running & Pace

Riegel Race Predictor

Dedicated implementation of Peter Riegel's 1.06 fatigue exponent equation

Input Parameters

Real-time calculation updates dynamically as you adjust inputs. Values remain strictly local on your device.

Predicted Finish TimeFatigue Factor 1.06

1:45:54HH:MM:SS

Target pace: 05:01 min/km (08:05 min/mile)

Clinical Responsibility Note: This calculation provides statistical estimations for informational and educational purposes only. It is not an individualized medical diagnosis or clinical prescription.

Mathematical Formula & Scientific Methodology

Formula: Riegel Power Law

T2 = T1 × (D2 / D1)^1.06

Accounts for the non-linear physiological reduction in speed over expanding distances.

Model Assumptions

Equivalent training preparation

Variables & Standard Units

Symbol	Physiological Meaning	Unit
1.06	Fatigue exponent empirical constant	dimensionless

Scientific Limitations

Extreme temperature or elevation will require pace adjustments

Peer-Reviewed Scientific Citations

Athletic records and human endurance (1981)

Riegel PS (1981) — American Scientist, 69(3), 285-290

Key Finding: T2 = T1 * (D2 / D1)^1.06. Fatigue exponent 1.06 models endurance degradation across running distances from 1500m to ultramarathon.

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