Iron men - and women

The Ironman (or 'full') triathlon is made up of a 3.8km swim, a 180km bike ride and a 42.2km run (a standard marathon) Photograph: Hugh Gentry/Reuters

The three disciplines require different techniques to those used when practising each individually. For example, the swimming section usually takes place in open water, so competitors need to see where they're heading and contend with currents and waves Photograph: Hugh Gentry/Reuters

The transitions between sections of the triathlon are crucial – you can lose valuable seconds putting on your shoes Photograph: Bruce Omori/EPA

After swimming, it's important in the cycling section to make sure you conserve some energy for the final running leg of the race Photograph: Chris Stewart/AP

While a marathon might be enough of a challenge for most people, Ironman contestants have to start theirs after the gruelling swim and bike ride Photograph: Hugh Gentry/Reuters

After a challenge like the Ironman, just finishing is a victory. Australian Craig Alexander did even better by winning the men's race in eight hours, 17 minutes and 45 seconds Photograph: Hugh Gentry/Reuters

British triathlete Chrissie Wellington crossed the finish line in nine hours, 6 minutes and 22 seconds Photograph: Chris Stewart/AP

Winning for the second year in a row, Wellington overcame a flat tire to beat last year's time by more than two minutes Photograph: Thomas Frey/EPA

Given the size of the Ironman challenge, a suitably large celebration is called for after crossing the finishing line Photograph: Hugh Gentry/Reuters