Figure 1: The decline in marathon performance of Whitlock, Turnbull and Hosaka.  Apart from a minor 'stutter' at age 70, Whitlock did not exhibit marked decline until age 80; Turnbull exhibited a similarly marked decline in his late 60's ; Hosaka shows a trend towards an even earlier decline. The data point at age 64 represents his time in the 2013 Gold Coast marathon.