I joined Imperial’s triathlon club in October 2011, with no real intention of ever competing in any triathlon; all I wanted was to come to the swimming sessions so that I could keep eating pies while a stress fracture healed. But even as Christmas rolled round and my foot went back to working order, I somehow didn’t manage to quit swimming. And every morning, no matter how gentle my intentions as I left home, I’d arrive at the lab a sweaty mess, after half an hour of silly commuter racing on my rattling, pannier-laden bike.

By the spring, I wanted to enter a triathlon. Come summer, another running injury and several conferences had meant I’d missed out on both BUCS triathlon events. Still, the itch needed scratching so I looked at the calendar and picked a race, finally opting for the ‘Olympic’ distance: 1500m lake swim, 40km bike on country roads, and 10km run around a park. It turned out to be the Triathlon England National Championships. Was I even allowed? Hmm … nothing about any qualifying times… I’d just have to go and do it, and hope to be swept along by the super-fit crowd sometime in the process.

Blessed are those who race with a club. I look forward to the camaraderie and minibus transport of the TriIC 2012⁄13 racing season. Getting to this race was a lonely faff: up at 3am to drink coffee, eat porridge, get my borrowed bike and a heap of kit into the car, and drive to Milton Keynes in the dark. I was so convinced I’d forgotten something that I asked a stranger to check over my kit.

The race begins with a mass of competitors treading water in the lake, going off in several batches or ‘waves’ separated by 10 minutes. Everyone knows you can slipstream on a bike, but I was surprised to learn you can do the same swimming — something I only realised after an annoying training session where someone kept swimming up behind me and tickling my feet, then slowing down as soon as he overtook.

In open water there’s another reason to ‘find a good pair of feet’ and follow them: it helps you navigate when your goggles have fogged up. Alas, it’s difficult to do in opaque water, and possibly cheating, so I mostly splashed my own way round, at a conservative pace since–even for a girl who loves a swim with the swans in Hyde Park–hyperventilating in the middle of a big deep lake sounds scary. Volunteer marshals dragged us up the slippery exit ramp as we finished swimming. No matter: I had already traded my dignity for a wetsuit.

Next task: removing said wetsuit. After a dispiriting session in my parents’ garden with a tube of KY jelly and a hosepipe, I found the perfect lubricant (it’s called BodyGlide), so this was a breeze. I even remembered where my bike was parked. Swim hat off, goggles off, helmet on, shoes on, slurp some sugary goo, grab the bike, get going, stop to tie forgotten shoelace, get going again, out onto the road where I am allowed to jump onto the bike and I’m free, chest heaving, pedalling out into the countryside and trying to get a bottle of sugary drink down ASAP because I know if I leave it to just before the run, it won’t stay down.

With most of the drink spilt down my front and legs, I gave up on it and put my head down. In this, as in most triathlons, riding in someone else’s slipstream was illegal. There’s an exclusion zone of a few metres around each cyclist; you can overtake as long as you don’t spend more than 15 seconds in that imaginary box. Despite various tactical quandaries, it turned out the bike was my strongest leg: the sun came out and I was able to overtake some people.

A veteran triathlete had advised me previously that ‘the run is just about holding it together’. With jelly legs and stomach cramps, all I could do was put one foot in front of the other and hope that meant I was going forwards. It was horrible, but I liked it. By lap 2 of 3 it was hot and a man with a hosepipe appeared and started sprinkling us. Ladies of ambiguous leg-letter overtook me and smiled sweetly. Later I heard footsteps behind me winding up for a sprint finish so I hoofed it off up the final straight, but it turned out to be a ghost.

I did the whole race without seeing a watch, bike computer, or clock - even the one at the finish line was broken - but expected to finish in anything between 2:30 and 3 hours. Imagine my delight, therefore, to find I snuck round in 2:28:57! Clearly, champagne and Doritos are the way forward in endurance sports nutrition.

We clapped in the last finisher, who won a ‘first prize’ and got the biggest cheer of the day (since separate prizes are given in each five-year age-band) when it occurred to me to ask about showers. “Most people just jump back in the lake”, they said– silly me!–and I dived back in to rinse off the sweat and lemonade. I think I’m hooked.