Coefficients and function fit for the asymptotic limit prediction.

Year calculated for achieving 99.95% of the asymptote with confidence interval (CI); b is the asymptotic limit; β is the progression range from the beginning of the event expressed as a percentage of the predicted asymptotic limit; β′ is the level of the actual BP expressed as a percentage of the asymptotic limit. Asymptotic limits b expressed in seconds for Oxford–Cambridge, Vasaloppet, Streif and speed ski record (for 100 meters); in minutes for the Hawaii Ironman and channel crossing; in hours for the Eastward, Westward transatlantic records and Elfstedentocht; in kilometres for the hour cycling records.