The Fat Man Diaries · Days 1–5

The Fat Man Is Keeping His Head Down

By Brian Cox · 23 September 2026 · Days 1–5 of 100

A long straight canal towpath under a blue sky — the hero image

I’m sitting in the sunroom writing this on the morning of September 23rd. Outside, it is one of those ridiculous Irish autumn mornings where the sky is completely blue and, for a few hours at least, you could convince yourself that winter isn’t coming. I have work sitting in front of me that needs to be done, various things requiring my attention, and all I really want to do is put my shoes on, get out the front door and walk.

That is probably the most surprising thing about the first few days of the Fat Man 100.

A week ago I was wondering how the hell I was going to fit 10 kilometres into every day for 100 days. This morning I’m slightly annoyed that work is getting in the way of me going out to do it, work can be a pain the arse sometimes.

I’m not getting carried away. We’re only a few days into this thing and I know the Fat Man well enough to know he hasn’t gone anywhere. The bollix is just keeping his head down.

The first two days were probably his best opportunity.

Because of work, family commitments and being Theo’s main carer, I couldn’t get out of the house for long enough to do the 10K outdoors. That meant getting part of it done early before everybody was up and fitting the rest around the day. Unfortunately, this also meant using my daughter’s walking pad.

I hate treadmills. I have now discovered that I hate walking pads even more.

There is something uniquely miserable about walking 10 kilometres while remaining in exactly the same place. Outdoors, even if you’re tired, at least the world is moving past you. There are fields, houses, roads, hills, dogs, sheep, people, weather and the occasional lunatic driver to keep you interested. On a walking pad there is a wall, a clock and the growing realisation that you've somehow paid money for a machine that allows you to walk absolutely nowhere.

My stride on it was all wrong as well; it’s shorter, and so my gait is shorter. Outdoors I can naturally settle into somewhere around nine-and-a-half to ten minutes per kilometre without feeling as though I’m pushing particularly hard and making sure I keep my BPM in Zone 2. On the walking pad I was plodding along closer to 12 minutes a kilometre, taking these short unnatural little steps. Somewhere during Day 1, right on cue, a hotspot started developing on my foot.

Day bloody one.

I remember thinking that if my foot was already complaining after a few hours, then perhaps the next 99 days were going to be more interesting than I had planned. I had to get outside if I was going to survive.

The bigger problem, though, was my head. A treadmill gives you far too many opportunities to negotiate with yourself. You can stop whenever you want. The button is right there. Nobody is forcing you to continue. You can step off, make a coffee and tell yourself you’ll finish the rest later. Or you can do eight kilometres today and twelve tomorrow. Or nine today and eleven tomorrow. Before long, the Fat Man has a spreadsheet open and is explaining that technically you’re still on target.

He loves that kind of shite.

Outdoors, especially on an out-and-back route, there is much less room for negotiation. If you walk five kilometres away from your house, congratulations: you have invented a compulsory 10K. You can have whatever internal crisis you like at the halfway point, but unless you intend to sleep in a ditch, you still have to walk home.

To survive those first two walking-pad sessions I had the laptop propped up in front of me watching people doing things considerably more ridiculous than I was. James Lawrence doing 100 Ironmans in 100 days. People running ultramarathons. Trail runners disappearing into mountains for 20 hours at a time. Basically, I needed to watch other people suffering so that my own suffering seemed slightly less stupid.

Even with that, time on a treadmill has a strange quality. You glance down and three minutes have passed. You walk for what feels like half an hour and another four minutes have passed; you start to say to yourself, don’t look down, don’t look down. Somewhere in Switzerland, scientists are probably studying this phenomenon.

Still, when I finished that first 10K, I felt good. Not heroic, not transformed, not like Rocky at the top of the steps. Just good. I had started. That mattered.

The walking pad set up against the window — the machine that lets you walk absolutely nowhere

Day 2 was more of the same and, if I’m honest, those first two days have probably been the low point so far. Not because they were particularly difficult physically, but because I realised there is absolutely no chance I would finish this challenge if I had to do the majority of it indoors. I need to be outside. That became obvious very quickly.

Day 3 was the first time I got out and did the full 10K properly, and the difference was immediate. My head was up, my stride opened out, the pace improved without any real extra effort and I was actually going somewhere.

Some of the roads I’ve been walking are roads I used to run years ago when I was training for marathons. You forget how much of that stays buried somewhere in your head. A particular gate, a bend, the top of a hill, a junction where you used to check your watch. Little markers I hadn’t thought about for years suddenly started appearing again.

For the first five days I’ve mostly stayed fairly close to home and used variations of the same general route. That will change. I want the next few weeks to become a bit more adventurous. Different roads, different trails, different places. I want the pictures and the stories to change too. One of the attractions of this whole thing is the idea that the 10K can take me somewhere rather than simply being exercise that has to be completed.

Back on the open road — the canal towpath under a rare blue sky

Then Day 4 reminded me that I live in Ireland.

Wind. Rain. Plenty of it.

I came home soaked, having also learned that the North Face jacket I had been confidently describing as waterproof appears to regard water resistance more as an aspiration than a technical specification.

Day 4: a misty country road in proper Irish weather

I’ll have to sort the gear out before winter properly arrives, but strangely I really enjoyed that walk. I’ve always liked being outside in that kind of weather, providing you’re properly dressed and you know there’s a hot shower waiting at home. There is something incredibly refreshing about rain hitting you in the face and a bit of wind blowing through you. It clears the head.

The Fat Man doesn’t seem particularly fond of rain, incidentally. I didn’t hear much from him that day, typical!

To be fair to him, he hasn’t really launched a serious attack yet. I suspect he’s confused.

For years he has had a fairly comfortable arrangement. He suggests the easy thing and, often enough, I eventually agree with him. Another bit of food. Start Monday. Do it tomorrow. You’re tired. You’ve had a long day. One won’t make any difference.

Now, suddenly, I’m putting my shoes on every day and walking out the door for 10 kilometres.

I imagine he’s somewhere in the background with his arms folded, thinking, “What’s this gobshite at now?”

He has made a few little appearances, mostly around fitting the walk into the day. That, more than the actual walking, is probably going to be the real challenge.

Ten kilometres takes me somewhere around an hour and forty minutes at the moment, but by the time I get ready, get out, do the walk, get home, stretch, shower and settle back into whatever I was doing, it has effectively punched a two-hour hole in the day.

Two hours is a big chunk when you already have work, family and caring responsibilities.

There have already been a few moments where I’ve looked at everything that needs to happen and thought, “Where the hell am I putting 10K into this?”

I suspect there will be days when that question becomes much harder to answer.

The Fat Man has also been popping up in his favourite disguise: food noise.

That battle hasn’t disappeared just because I’ve started walking. Far from it. But I’ve noticed something that has happened to me before whenever I exercise regularly: I become much more conscious of what I eat. If you’ve just spent the best part of two hours walking, there’s something particularly stupid about coming home and undoing the good work by eating half the kitchen.

That doesn’t mean the urge goes away. It just means I’m hearing the conversation a bit more clearly.

And for the moment, I’m winning more of those conversations than I was.

By the end of Day 5 I had done 50 kilometres.

The road ahead — five days down, ninety-five to go

Fifty kilometres sounds impressive if you say it quickly, but it really isn’t the point. Anybody reasonably healthy can go out and walk 10K. I don’t think there is anything especially remarkable about what I have done so far.

If I’m still doing it on Day 50, that will be different.

If I’m doing it on Day 75, when the novelty has gone and nobody is particularly interested anymore, that will mean something.

If I’m putting my shoes on in November when it’s dark, cold, wet, I’ve had a rotten day, Theo needs me, work is piling up and every part of my brain is telling me to skip it just this once, that is when I’ll find out what this challenge is actually about.

For now, though, I’ve started. The routine is beginning to form and, slightly unexpectedly, I’m enjoying myself.

It is starting to feel less like something I have to squeeze into the day and more like part of the day itself.

Which brings me back to this morning.

The sky is blue. The shoes are sitting there. I have work to do.

And the Fat Man is very quiet.

I don’t trust the bastard for a second.

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