According to my Collins Little Gem dictionary, the word ‘Iso’ means ‘equal’, and is typically used as a prefix to words like ‘Isochron’ and ‘Isotope’, which sound faintly sinister and suggest people in laboratories meddling with atoms.


This definition was news to me because the only time I’d ever heard the word before was when England footballer John Barnes used to drone on about Isotonic drinks in Lucozade Sport adverts in the 1990s. 

That was until I heard about a new and exciting triathlon event, the Isoman – exciting because some race organisers had been in a lab of their own, meddling with the format of Ironmans to come up with the concept of ‘triathlon equalised’. Chief lab-based race directors, Gary Jarvis and Phil Walker, worked out that most triathlon distances seem somewhat biased towards cycling and running, with only 10% of the total race time spent swimming, 50% cycling and 40% running.