Triathlon done: the worst - and best - experience of my life

That's it. It's done. The stupid triathlon, the bane of my life for past two months, has been completed, and I never have to put on a wetsuit again.

It all began at 4.25AM, when the alarm went off and I had to roll out of bed with just two hours' sleep in my body, the worry of not waking up doing that wonderful thing where you just can't drop off.

I'd thankfully laid out every single step of putting on clothes the night before, so I didn't make any mistakes and leave without any trousers on - but even still, the simple act of filling up two water bottles, making some porridge and remembering to pick up my bag was nearly too much for me.

Train as I might have, there was very little chance of me making it around through the 750m swim, 30km cycle ride and 5km run without my cycling shoes or wetsuit.

I made it to the transition area, where I'd racked my bike the day before, at 5.45AM (following an unexpected traffic jam on the way into the car park) with my swim beginning at 6.04AM. And it was about 10 minutes walk away.

I hastily pulled everything out of the bag, placed it in order (no chance of me trying to put a t-shirt on over a helmet THIS time, pals) and then began to chuck on my wetsuit. "It's now two minutes to six - if you're in the 6.04 or 6.08 wave, you really need to get to the water" came the voice over the tannoy.

I looked down at my watch. It said 5.53. Not wanting to dispute the time with, well, nobody around, I shoved my bottom half into the wetsuit and began to run. In bare feet. Over gravel down to the water.

While racing down, I put my googles on. I realised that was a bit soon. I took them off. I put my hat on, then realised my race number wasn't on, so tried to trot, look for roots or other things to trip over while sticking a number on my head and praying it was the right way around. All the while lubing up my neck with the Body Glide anti-chafe stick I'd been recommended so I didn't rub half the skin off my head with my wetsuit.

I made it to the water just as the safety briefing began then jumped in with all the other orange-hatted fellows and was instantly glad of the A:1 wetsuit from 2XU.

Having never tried a 'normal' wetsuit (ie one without the front flotation zone) I can't vouch for the buoyancy of others, but any regular readers will remember: I can't tread water and I was going to need to for about two minutes.

It didn't matter. It was like being in a warm armband. The klaxon eventually went, I hit go on the Garmin 920 XT on my wrist, and we were off swimming. Not only that, but even being in the middle of the pack I didn't get kicked, swum over or all the worrying things that people had told me. This was going to be great!

Except… that feeling lasted about 2 and a half minutes, the point at which I approached the first buoy, probably marking about 100 metres in and I was already struggling. I hadn't managed to put my wetsuit on properly in my haste and I was convinced it was making me dizzy. I was going to drown. There was no way out. I couldn't get out the river.

In one of the genuinely worst moments of my life, I began to really panic. I was stuck. I wouldn't be able to finish. I'd have to be rescued three minutes in. This was terrible. I wasn't even swimming with my head in the water already and I was in trouble.

I tried to calm down, remember it was the open water, the adrenaline and the early start, but it was no use. I started doggy paddling. In a triathlon. With grown-ups watching.

The dizziness would abate, I'd feel OK, and I'd start front crawling again, heading past those people smartly breast stroking. Then I'd crash again and go back to labrador mode.

This continued on for 15 minutes, until I mercifully reached the red buoy, signalling the end of the swim. I turned around it, ready to head for shore, praising the thought that I'd never have to swim EVER AGAIN… and saw there was another 100 metres to go.

The panic set in once more. I couldn't make it. I HAD to get out. I moved closer to a nearby boat, wondering if I could pull myself up that way… then I felt it. The floor beneath my feet! I could walk and pretend to swim!

However, one stroke of that and it was clear NOBODY would believe I was swimming. I looked ludicrous. So, back to the doggy flopping through the water, and somehow I reached the dock (by this time the group which started 10 minutes later had begun to overtake me, looking all professional with their lack of fear and high swimming ability).

Then came the transition, a lot of sopping wet men trying to get undressed while running to a cage full of bikes.

It's hard enough finding your bike in the park after work, let alone a bit dizzy, sleep-deprived and at speed. I managed to locate it though (mostly because my Laser helmet was Union Jack-coloured) and even managed to put on my clothes in the right order before grabbing my bike and heading off to the mount line.

I decided to put on a t-shirt, even though it would slow me down and it was warm enough to not need it - I had a trick up my sleeve. Well, it was THE Trick, from X Bionic, which has a special strip to heat up my spine, make me sweat quicker and thus peak faster. Genius.

If I hadn't put it on backwards.

The cycle itself was rather nice - the Pearl Izumi shoes and Tri Suit I was wearing worked nicely in tandem to keep everything sensitive from getting squished on the hard saddle, and being clipped into the Shimano cleats really makes it easier to cycle.

The shame was my bike was just my boring old Giant Rapid 400. It's not fair to call it boring, but there were loads of units shooting past me that cost more than my car - and I was supposed to be trying one out for this triathlon, to write about how much better the experience was with top end bike tech.

But that fell through at the last minute, so here I was with the daily commute bike, one of the few without racing handlebars and DEFINITELY one of the only ones not to have taken off his mudguards and creating massive drag to slow him down. I didn't think, at the speeds I'd be travelling, it would matter - but it really does after 54 minutes of pedalling.

The cycle was actually better than I was expecting, with my Garmin set to bleep should I fall below my desired average speed. The Wahoo Tickr X heart rate monitor - which doesn't work in the water - was now back pumping out my heart rate too, and even with the added speed I was finding my heart rate was staying nice and low.

All that remained was to follow the advice of the Maxinutrition specialists of taking my gels at the start and the end (pro tip: cut an elastic band open and use that to tie them onto your handlebars as an easy way to grab them on the go) and keep drinking my electrolyte drink every 15 minutes.

I quickly started deciding on people I should be beating and those I shouldn't: man with his name on his back? He's mine. Man who looks a bit like a mix of Ming the Merciless and David Gandy? He's probably faster than me. Man who has a similar bike to mine but with better handlebars? He's going down.

This continued for three quarters of an hour through beautiful Windsor countryside (which ended with me watching all the aforementioned characters shoot off into the distance while my leg started to hurt) before the town rolled back into view.

And, get this: I even managed to remember that you need to unclip from your bike before you can dismount when wearing pedal cleats!

Easy way to train yourself to remember to do this: go training with your bike, complete with shoes and cleats, forget ALL ABOUT THEM at the traffic lights, and fall over sideways when you realise you're locked in, in front of a lot of stationary cars with the windows open so you can hear the drivers crying with laughter.

Not this time. This time I'm smartly running my bike back to my spot, flipping off my velcro shoes like a confident 5 year old. Bike racked, helmet off and then to the best bit: slipping on the Adidas Ultra Boost trainers.

It feels glorious. Not only because these trainers have a tongueless design (so it's more like wearing cushioned slippers) but because I'm running - this is the bit I can do, and it's the only thing standing in the way of me having to never triathlon again.

Except my legs aren't working properly. I try and do some fancy limb flipping to get them going again, but they seem out for the count. I shrug. It's still better than swimming. Then again, so is jabbing a pencil into your arm over and over again.

I set off on the run, trying to get some motion going, only to be faced with a massively steep hill. I employ a technique I learned reading 'The Art of Running Faster': imagine you're a bike.

If you were pedalling up an incline, you'd drop down a gear and spin faster. The same applies: smaller steps, quicker pace, and soon I'm flying past the competition, descending back down again before I know it.

And there's the finish line! My word, that was fast. I haven't even had time to look down at the Garmin to see how fast my kilometres have been. Wait, why are there two signs? What do they say?

'Finish line'. 'Turn around for lap'.

I breathlessly ask the girl next to me: 'How many laps is this?' 'Three' she replies nonchalantly, before legging it off to the finish.

Balls.

However, it's still only 15 more minutes and two more attempts at that increasingly stupid hill and I'm back here for real, haring down the straight with abandon of a man coming home for war and seeing his darling in the distance.

Only it's not that. It's the end of having to do triathlons forever, and it's the best feeling in the world.

I actually tear up as I cross the line in a time of 1hr 43 mins. No more wetsuits. No more cycling. No more anything to do with open water swimming ever again.

Even though... I definitely could go faster with a better bike (or even fewer mudguards), and if I was a little braver with the swim I could have easily knocked off 4 minutes by just, you know, actually swimming and I could have structured that run better if I'd looked at how many laps….

Oh, crap. This isn't the end.

• Huge thanks to Madison and 2XU for supplying me with the triathlon kit, and to Windsor Triathlon organisers Human Race for stopping me from drowning by letting me change distance at the last minute.
• If you've got any tips, tech you want tested out or just want to mock me, I'm @superbeav on Twitter, and you can see my stumblings on Strava too.
• Read the rest of the Running Man of Tech story here