Jonathan Drennan: Ironman pushed me to my limits, and I still question why I did it

I knew the risks, but I naively refused to believe that I could ever be in serious danger.

The start of the cycle race at Ironman in Youghal on Sunday. A full-distance Ironman takes place over 140.6 miles, with a 2.4-mile swim, a 112-mile bike ride and a marathon to finish. Picture: John Hennessy

On the stairwell of my apartment, there is a crinkled bit of paper in a frame, with a number and the Irish flag. It is my race number from Ironman 2016 in Nice, France. I completed the event in just over 11 hours, and have never returned to do any further events. 

A full-distance Ironman takes place over 140.6 miles, with a 2.4-mile swim, a 112-mile bike ride and a marathon to finish. I know that doing that Ironman pushed my body and mind to its limits and I still question why I did it.