Chrissie Wellington is quite possibly the greatest triathlete to have graced the sport: holder of all Ironman world and championship records, undefeated in 13/13 Ironman-distance races, and 4-time Kona winner, with the first being less than a year after turning pro in 2007. She never thought of becoming a professional triathlete, and instead focused on succeeding academically and pursuing international development as a career.

After her first marathon at the age of 25 and her first triathlon a couple of years later, Chrissie trained "obsessively and compulsively" to reach where she is today. Chrissie's determination, inspiring smile and remarkable class remind us why we love the sport.

Some of Chrissie's advice:

"On my race wristband, and on all my water bottles, I write some simple words. One is 'smile' and the other 'never give up'. I always say that Ironman is 50% physical and 50% mental. To plunder the words of Mohammed Ali, 'the will must be stronger than the skill."