Centurion Running Thames 100: What goes through your mind before you run your first 100 mile ultra

Centurion Running Thames 100

On Saturday 29th April 2017, I’ll attempt something that for most of my life I would have believed was utterly impossible. I’m running my first 100-mile ultra, the Centurion Running Thames 100.

The race tracks the river Thames as it snakes from Richmond up to Oxford, via Slough, Henley and Reading. Around 350 runners will have 28 hours to cover the 160km distance along compacted trails, soggy fields and the odd town centre. Starting at 10am on Saturday morning, those of us who conquer the course before the clock strikes 10am on Sunday morning – that’s under 24 hours aka 1,440 minutes – will become the proud owners of a belt buckle that says ‘100 Miles in One Day’. 

For anyone unfamiliar with ultra racing, it’s quite commonplace for  running endeavours of a certain distance to earn you a belt buckle rather than a medal. Despite having six ultras under my, um, belt, I still don’t have a buckle.

As I prepare for what’s guaranteed to be the biggest challenge of my running life yet, my mind has already started racing with dozens of questions. So if you’ve ever wondered what troubles the little grey cells in the final days before you run 100-mile ultra, here it is. 

How do I feel?

After every training session, during every last run, when I wake up, when I eat lunch, before I go to bed, in the shower, no matter what I’m doing the same question keeps popping into my head: how do I feel right now about what I’m about to do? The only way I can describe this is that it’s like my brain is replicating that bit on a roller coaster where the cars climb to the top to build up all the potential energy. This is my brain winding itself up, hopefully storing the mental energy I’m going to need fire me to the finish, via plenty of stomach churning loop the loops along the way no doubt.

The worst thing about this is that the answer to these questions isn’t always positive. Sometimes the response that comes back from Panic Merchant Me is…

‘I’ve definitely got a cold, an injury and I’ve forgotten how to run’

The closer you get to race day, the more the slightest cough, twinge or harder-than-usual mile makes you think the worst. As I sit and type this I’m convinced I’m carrying a minor tummy bug, my chest is feeling a bit tight and for some reason yesterday’s steady 10k has tightened my hamstrings. At this point it’s important to breathe and focus back on the positives. Among my favourites are: all my favourite running socks are clean, I’ll get to eat eight sachets of Pip & Nut Almond butter on the day and remember, this is just a big long stroll with snacks. 

Centurion Running Thames 100 Training Plan

Have I trained well enough?

This question isn’t unique to a 100-mile ultra but when you’re dabbling in three-digit distances the potential for self doubt becomes even more heightened. It’s all too easy to analyse your training schedule and weigh up the potential cost of all the times where you might have skipped a session because life got in the way or made a smarter decision and eaten better.

By the time I line up for the Centurion Running Thames 100 I’ll have completed a 29-week training programme with approximately 50 strength sessions and 55 running sessions of varying distances. Could I have trained more? Possibly. Could I have eaten a little more optimally? Definitely. But there’s no sense worrying about that now. At this point it’s crucial to trust in the training you have done and clear everything else to one side. 

Am I mentally tough enough?

From the safe distance of a few months until the race it’s easy to diminish the true mental cost of that cones with running longer ultras. It’s easy to think you’re capable of completing anything you set your mind to. But as you get within a few days it’s inevitable that you start to question how tough you really are. Have you got what it takes to push through?

And it’s only when you’re deep into doing the miles during the event that running reminds you just how hard it can be. To prepare for this I try to go back to the moments in races where I’ve suffered the most and still come through. Conjure up that spirit and reassure myself that this is just the same. It’s what legendary ultra runner Marshall Ulrich nods to in his 10 Commandments of Endurance when he says ‘Expect a battle’. 

Ultimate Running Watch

How fast should I run?

This question should really be ‘how slow should I run?’. If there’s one thing I’ve learnt the hard way about ultra running is that you pay a hefty price for going out too fast. When you go out too fast over 26.2 miles of a marathon and the wheels come off at mile 20, you can still dig deep and drag your arse to the end. It’s a very different story when your engine blows up and you’re staring into the 50-mile abyss that stands between you and the finish line. And so discipline is everything.

My race plan for the Centurion Running Thames 100 is simple, metronomic 12 min/miles from start to finish. With time for a cuppa tea at a few aid stations that’ll get me round in under 24 hours. That’s just four miles an hour, half the hourly distance I covered running my fastest marathon pace. It’s painfully slow going  but accepting the rate of progress is crucial. I have to keep telling myself that the 95-Mile-Deep Me will thank Early-Miles Me for being smart.

What happens when it gets dark?

I’ve run long races in the dark before. The long day of the Marathon des Sables, the Lavaredo, the 24-Hour Thunder Run and that one time I tried to do a practice run in the New Forest and only lasted 45 minutes because it was terrifying. For the Lavaredo we started at night and ran through the following day so there was a huge novelty factor at play which almost made the night fly by. At the MDS I ran for 13 hours with a handful of the latter miles in the dark. The Thames 100 will be different.

It gets dark at 8:32pm, I know because I’ve checked. At this point I should be at the Henley aid station about 51 miles and 10 hours into the race. I’ll have my family here, I’ll be changing in to some clean socks and maybe some warmer gear. The lights of Henley’s river pubs will be glowing tantalisingly all around. And then I’ll have to get off a chair, leave a warm tent, say goodbye to my family and run off into the dark. For another 9 hours until the sun peeps it’s head up at 5:31am.

This will be one of the loneliest moments of the race. I know I’m going to feel vulnerable, exposed and like I just want to go home. The prospect of running alone along the Thames in the darkness with 50+ miles already on the clock is pretty daunting.

So I’ve called in the cavalry. Remember this guy I finished the Bright Marathon with? Well he’s kindly agreed to pace me from 2am through to 5am. This crucially gives me something to look forward to and carries me within dribbling distance of what should be one of the best moments of the race, sunrise. 

Will I need to sleep?

This is the question everyone has been asking me and I have started to wonder myself. I have run for 21.5 hours overnight without the need for a kip and so I’m going into this race with the aim of staying awake. I guess my body will soon let me know the answer.


What should I eat?

The aid stations on ultras are a 7-year-old’s sugary dream. These pop-up tuck shops carry everything from flat coke and flapjacks to Haribo and jelly babies. But until now I’ve always avoided them, I prefer to carry my own fuel. But I’ve never run 100 miles before. And I’ll be the first to admit that struggling with nausea late into races is one of my biggest problems. So right now this is one of the questions making me panic.

The plan as it stands is to use a mix of Generation UCAN and Poliquin Rise in bottles that I sip religiously for an even, steady flow of carbs. The only problem with this is the taste. After 20 hours it can get a bit much. I’ll mix this up with 33Shake Gels, the only gels I’ve found that actually taste lovely.

At certain aid stations I’ll also be having a combination of a 33Shake, Herbal Life protein and fish oil tablets and I’ve stocked up on dates, dried figs, Primal Pantry bars, Ella’s Kitchen fruit pouches and Pip & Nut almond butter sachets to plug any gaps. I’ve also found water melon to work well in the past when my stomach’s in a bad way so that’ll factor too, along with the odd cup of sugary tea and potentially some Knorr chicken noodle soup. 

I’ve also packed salt tablets that I’ll take with each 750ml bottle of water I drink to make sure my electrolyte balance is stable.

What happens at Mile 63?

The furthest I’ve ever run is 100km. That’s 62 miles give or take a few hundred metres. So I have no idea what happens beyond that point. This is where I’ll literally be running in to the unknown. I’m presuming that it’ll be more of the same with fluctuations in mood, pace, belief and positivity. At least that’s the psychological part what’s less clear is how my body will hold up after that point. 

The longest I’ve ever run is 21.5 hours and that was up and down mountains so I’m hoping it won’t be much worse than that. But there’s only one way to find.

Follow my Centurion Running Thames 100 live (sort of)

Follow Manvmiles on Facebook, Instagram or Twitter for updates as I take on the Centurion Running Thames 100. I’ll be posting as often as my tired brain will allow during the day. If anything to take my mind off how much my body hurts.