
Yesterday I set a new personal best (PB) for the Finsbury Park 5k Parkrun: 23 minutes and 50 seconds – 5 seconds faster than my previous PB, set on 22 February and a full 170 seconds faster than my first (completed – there was a previous failure!) run on 29 June last year.
To beat Mo Farrah in a re-run Olympics I need to shave another 10 minutes and 9 seconds – 609 seconds – off my time. Easy – at a linear rate of improvement I will manage that in another 2 years and 10 months. Rio here I come!
But why stop there: you will have noticed I have also taken 3.4 seconds off my 100 metre time. To be the fastest man in the world and beat all comers with 9.5 seconds for 100 metres I need just wait another 5 and a bit years.
Of course, I’m never even going to come close. My rate of improvement is slowing rapidly. A full 57 seconds of that 170 seconds – in other words more than one-third of it – came in the week between 29 June and 6 July last year.
Even the current rate of improvement – 5 seconds over 7 seven weeks – probably won’t be sustained for very much longer. And even at that rate I wouldn’t be beating Mo for another 16.4 years – by which time I’ll be 65.
The moral is: beware of linear projections.
But if I train a bit harder…