2007 and 2018 Age Factors

The age factors in Table 1 in Fair (2007) were updated through 2018 in Fair and Kaplan (2018) for the "run" category, which is all running events between 5km and the marathon. The updated estimates are based on world single age records for men compiled by ARRS: World Single Age Records. Four road races were pooled---5km, 10km, half marathon, marathon---along with two outdoor track events---5000 meters and 10000 meters. The data are as of June 2, 2017. The following is a comparison of the old and new results:

2018 versus 2007 Estimates

alpha^age^delta^R50R60 R70R80R90R95
20070.008075.10.001641.081.171.27 1.432.152.99
20180.009877.60.002221.101.221.34 1.502.303.36

The 2018 work began at age 40 rather than 35, and the 2007 age factors above have been normalized to have R40 equal to 1.00. The R's are the age factors at the various ages. The age factors are quite close until about age 90. The updated estimates are more pessimistic about decline rates in the very old ages. There are few observations beyond age 90, and some of the existing records are undoubtedly soft. The estimates beyond about age 90 are thus not trustworthy. More observations at the very old ages are needed before much can be said. Because of this, no extrapolations in the new work were done beyond age 95. The oldest age in the estimation work was 95.