Mark Daly, 34, is BBC Scotland's Investigations Correspondent. This year he is taking up the Barcelona Challenge - an Ironman distance triathlon: a 2.4-mile swim, followed by a 112-mile cycle, finished off by running a marathon - 26.2 miles.
Here he brings us the latest news from his preparations with only four weeks to go until the big day.
Mark crosses the line at Vitruvian in four hours 39 mins
I am writing this on the train on my way home from yet another preparation race, with yet another pair of incredibly stiff legs.
I'm getting used to the pre-dawn race-day rises and getting by on hardly any sleep (which I'm sure my wife is taking as an indication that I'm ready to start a family), but there are many other aspects of being a triathlete that make me question the sanity of tri devotees, never mind my own state of mind.
Take last week, for example. I'd managed to get a late entry into the Honey Stinger Gullane Beach open water triathlon.
It's an extremely tightly run race with a good reputation and always sells out, so I was pleased to get a place.
But, as usual, I had to eat breakfast three hours before I generally like to get up and, as usual, it was raining when I left, so I was already in a bad mood by the time I arrived in Gullane.
My mood wasn't improved one bit when I copped a look at the sea. These were conditions more suited to surfing and, not for the first time since I signed up for this madness, I thought about an exit strategy.
I normally quite like competing, but I don't much care for attempting to pedal into a 40mph head wind, nor for that matter ploughing through four-foot waves with 200 other rubber-clad menaces trying to swim over over/under/across me, kicking, pulling and scratching while they go.
Oh, and the water temperature was 13 degrees.
I don't mind admitting that I've had a bit of a mid-season slump - I had underestimated how much commitment training properly for the Barcelona Challenge would demand.
I tried to follow an Ironman training programme (up to 18 hours per week) which turned out to be impossible, so I've been left to try to work my own programme out, slotted in around work.
So I know I haven't done the hours that most would recommend, but I'm hopeful it will get me through. And that's exactly what I hoped to do as I lined up on the beach at Gullane - just get through.
I had been slightly cheered by the news that the swim distance was being halved from 1500m to just one lap of 750m due to the size of the waves.
And, before I knew it, the hooter had sounded and I was in and away.
The swimmers create a "washing machine" churn at the start of the 1900m event
The swim is supposed to be my strong leg, but fighting against these waves meant my front crawl had more comic value than aesthetic grace.
But, 12 minutes later, I was hauling myself out the water in 15th place.
A lung-bursting run up and over the sand dunes to the transition was challenging enough, but by the time I got on my bike for the 42km middle leg and turned into the wind, the stuffing had been well and truly knocked out of me.
Sidewinds were also a hazard, preventing me from using the aerodynamic racing position; I was simply focusing on not being blown off.
A steady bike leg in 1 hour 20 minutes brought me into the hilly 10km run, where I was quickly lapped by eventual winner Fraser Cartmell.
No shame of being lapped by this guy, though, as Fraser is twice UK half Ironman champ.
Thinking of moving up to Ironman distance next year, Fraser, a thoroughly decent, down-to-earth guy, was only too happy to stop at the end of the race and pass on some much-needed tips.
I also bumped into my boss, Atholl Duncan, on the run section as he was grinding out a very respectable 2:47. He has also got the tri bug and might well be tempted by Barcelona next year.
I was quite happy with my 45-minute 10k in a run that could only be described as brutal. Overall, I came home in 2:22 in 40th place overall. The Gullane beach triathlon is a great event, but it's not for the faint-hearted.
Mark with triathlete Fraser Cartmell, who lapped our man in the 10K
Next up was the much-hyped Vitruvian triathlon in Rutland Water, Leicestershire. Over the half Ironman distance (although the bike leg is irritatingly four miles short, at 52 miles), this was going to be my final preparation race before the big one.
I travelled down on Friday night with training partner and Daily Record reporter Mark McGivern and we were immediately struck by the size of the event.
The Vitruvian, run by Pacesetter events, accommodates 1,000 of the UK's best amateur triathletes and at least as many spectators and has been voted triathlon of the year twice running.
And, after the horror of another 4am alarm call, we were beginning to see why.
The 1900m swim was a dream. I was off in the second wave, which contained around 300 swimmers and we were to loop round a distant buoy.
But the buoy seemed to be directly below the sunrise, so every time I lifted my head to breathe and spot my route, it seemed like I was heading straight for the blood-red sun.
I had to put in a spurt in the first 50m to get out of the usual "washing machine" churn of a triathlon start and I was soon into a decent rhythm.
A personal best of 28 minutes and I was out the water and searching for my bike. It was only 7am, but already there were hundreds of people there, cheering us on. I felt like a real athlete!
The 52-mile bike leg was mainly flat, save for a few minor bumps delicately named the "Rutland Ripple". And, compared to Gullane the week before, they were nothing.
Lovely smooth roads and mild weather allowed me to average about 20mph all the way round and I finished in 2:32.
Then it was into the final leg - a 13.1 mile run - usually my weakest event.
For the past two months, I've been doing a speed session every Wednesday with the BBC's marathon man Bryan Burnett and some other fast guys and it really felt like it was paying off because, for the first time since I started all this, I didn't feel like chucking it halfway through the run.
I had been careful about my energy gel intake, so no stitches or cramps this time.
In fact, I seemed to get faster through the miles and I finished very strongly.
Mark puts in the miles ahead of his big challenge in Barcelona
Experts say that, after a swim and cycle, you should aim to run within 10% of your personal best for the final leg, so I was delighted with 1:34, just five minutes outside my fastest-ever half-marathon time.
The finish area was party central - blasting dance music and enthusiastic announcers calling the names of every athlete coming home.
So, when I heard my name, I put on my best Usain Bolt to fly over the line in an overall time of 4.39.00 - and in a surprising 69th position.
To say I was pleased would be an understatement and I wasn't the only one.
The look of joy on every athlete's face as they crossed the line was a picture and testament to the best event I've raced this year.
With less than four weeks to go before the big one, the Vitruvian was the perfect tonic to my training slump, providing a much-needed confidence booster that I might manage round this monster course in Barcelona without actually killing myself.
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