Every Tuesday after my swim coaching I get on the tube with wet hair, eat a sandwich and try to shake the water out of my ears. Often I’ll read a book or catch up on twitter. This week was no different other than that I’d swum 1500m during the course of the session.

“That’s an Olympic tri swim!” I said to my coach after she’d added up my lengths.
“So it is.” She’s rather matter of fact about these things.

I headed off for a hot shower, excited at what I’d just done. It was another milestone reached. There’d been some stopping either end of the pool to catch my breath, but I’d just swum as far as I’d need to swim in the Marlow Triathlon next summer.

I was grinning like Chrissie Wellington as I got on the tube, ate my sandwich (prawn much to the displeasure of my fellow passengers) and reached into my bag for a book.

This week’s reading of choice was ‘A Life Without Limits’. Inside the front cover, staring up at me was the message Chrissie Wellington had written to me last summer, before I’d even had one swimming lesson. It reminded me of the promise I’d made her to complete an Ironman.

And so, buoyed by a possible over-calculation of my swim distance and encouraged by the four-time Ironman world champion, I’ve signed up for a half-iron distance triathlon which is reassuringly called The Gauntlet.

In September 2013, I’ll be swimming, biking and running my way 70.3 miles round a triathlon course. I’m not entirely sure this is a good idea, but I’ll give it my best show and, as Chrissie says, ‘Never give up’.