How I Ran My First 100km – Race To The Stones

How I made the jump from 42km to 100km in a single event – Race To The Stones – with no specific training, and finished in under 12 hours . . .

Last July, I ran my first 100km ultra-marathon – Race To The Stones, along the Ridgeway in South England.  Despite not training specifically for the race, I completed the race without too much pain – and got to the finish line in 11hrs 39mins.  Having previously only ran for a maximum of 42km, how did I manage to survive the step up to 100km?

Making The Leap To 100km – Signing Up For Race To The Stone

Like many people who have managed to complete a marathon, once my feet had recovered and I’d suppressed most of the ‘I’m-never-doing-this-again’ mid-race thoughts, I began to wonder what else I was capable of.  The same voice that pushed me to sign up for my first marathon was now nagging me to see what else was out there.

The idea of running something as long as a 100km race was daunting, and not particularly appealing – why would I want to try and run for that long?  Surely that’s not good for your body?  It’s just going to be endless hours of discomfort, right?  Still, that same internal voice persisted in looking for a new challenge.

My friend Megan happened to mention she was running the Race To The Stones 100km through South England in a few months, and why don’t I join her?  On a whim, I loaded up the race website and keyed in my details.  I told myself that I wasn’t actually committing to the race, just penciling in my interest – I could easily pull out at any point.

As the race approached, Megan had to pull out due to a knee injury – it would have been the perfect excuse for me to pull out too.  But instead, I quietly kept the race at the back of my mind, and as the summer approached I tentatively booked flights and hotels – I didn’t even tell any of my friends or family about the race, I was so apprehensive.  All they knew was I was going to do some run outside London.

(As a disclaimer, I should mention I did run a couple of stage races in the 12 months before my first 100km – however I walked the majority of these, and the longest distance I’d covered on foot in one day was 77km – which I walked.)

The Map - the route heads from East to West
The Route (goes from East to West)

The next thing I knew I was at Heathrow bus stop just before 05:00am on race day, waiting for a bus to Oxford, dressed in my running gear.  A couple of hours later, I was at the start line . . . completely oblivious as to how the day was going to unfold.

Then we were off.

So how did I finish the race in 11hrs 39mins when my training had just been a couple of 10km runs and a few gym sessions per week?

The Start Line

Ten Small Races – Divide Up The Route

For most of us, 100km is too far a distance to really comprehend covering by foot in one day.  We’re used to training for a few hours at weekends, but nothing on this scale.  The distance, and also stimulus along the way, can be overwhelming.  So don’t look at it like one long event.  Break it into 10 small ones.  Fortunately, at these events each checkpoint is roughly 10km apart, so these are your perfect bite-sized chunks.  Every runner knows what a 10km feel like in their head, so just tell yourself you are doing a 10km run each time.  If it helps, mentally picture yourself running your familiar 10km route back home.  Never think beyond the next checkpoint.


In ultra-distance events, if you feel you’re pushing your legs hard then you’re probably going too fast.  I never push myself beyond a comfortable ‘conversational’ running pace in these long events, because I know I need to save my legs for the rest of the race.  Maybe in the last stage I’ll start to dig deep, but otherwise don’t think you’ve got to hold a certain pace – let your comfort level dictate your speed, not the other way around.

Through the fields
Through the fields


My goal in any race is even splits – this means a consistent speed throughout the race.  If you see someone at a finish line that has just run on even splits, they’re usually fairly comfortable, smiling – they’ve just completed a race at their planned, consistent speed.  It’s inevitable that on longer races you slow down as your body gets tired (my first 50km took 5hrs 30mins, my second 50km took 6hrs 10mins – not perfect, but  more consistent that almost every other runner).   Don’t fall into the trap of going too fast to start with, then suffering later on.  If you stick to a comfortable pace and medium-exertion-level, an even split should come naturally.

Pounding the trails

Under-estimate Your Pace 

Here’s a psychological trick I play with myself, that seems to work (I’m weird) . . . at each checkpoint, I ask how far it is to the next checkpoint, then over-estimate how long it will take me to get there.  So if it’s 10km between checkpoints and I know I’ve been running strong, I know I should take about 60-70 minutes to get to the next checkpoint.  But I’ll add in some fat, and tell myself I’ll take 80-90 minutes to get there.  This way each checkpoint comes in ‘early’ and you feel good.  On ultra-distance runs, any little trick like this to give you a boost helps.

4 - me
Trying to maintain a conservative pace…

Don’t Sit Down

I’ve learned that sitting down at checkpoints is dangerous, at least for me.  If I sit down when I’m tired, it takes a serious amount of willpower to get back up.  Instead, I try and zip through checkpoints – when I see one on the horizon, I neck my salt tablets and get my water bottles ready, then when I reach the checkpoint I just fill up on water, grab snacks and keep moving.  If I am tired and need a breather, I’ll walk for 5-10 minutes after I’ve left the checkpoint – this gives me a chance to drink, have a gel, etc.  As you get further into the race, the lactic acid builds up in your legs and the last thing you want to do is stop moving them!

A Nice Sign

Know Your Guts

From my stage races, I knew what my guts were capable of handling when out in the heat for hours at a time.  I’m lucky, I can chug gels at a rate of one every hour without any adverse affects, and can snack all day too.  I also know I can’t handle anything dense, like a Clif Bar or a proper meal while running.  But I learned this through testing before entering the 100km race – I didn’t trial anything different on the day.

Cow action on the trail

Schedule All Your Intakes

Gels, snacks, salts, water.  That’s all you’ve got to remember to take, yet it’s amazing how easy it is to get mixed up and forget to take something.  I typically use two things to schedule my intake – checkpoints, and the hour hand on my watch.  For gels, I’ll take one every hour, on the hour.  For salt tablets, I take one or two every checkpoint.  But everybody is different – so plan your schedule before the race starts and stick to it.  For water, I follow the rule of regular sips to stave off thirst, rather than drinking more than I feel like – your body always tells you what to take, if you can listen to it.

The fabled Avebury Stone Circle


OK the big one – I turned up to this race with no specific training, I was just running a couple of times a week with friends if I found the time, and was going to the gym regularly.

Now, this doesn’t sound like enough, but the truth is this was perfect for me.

I’d been running one or two marathons per year for two years by this point, and had previously built up a really solid base of ‘running training’.  My one or two short runs per week were just topping up this base, without pushing my legs or risking injury from over-training.

My gym sessions, meanwhile, covered my whole body – including legs  And although this wasn’t a specific training programme, this strength is really important when it comes to the endurance required to run 100km in one shot.

While my training seemed haphazard and a bit aimless, the truth is I was following the simple rule of working out for 1 hour per day, be it cardio or weight training.  This, combined with my  existing base of running fitness, is what got me to the finish line in good condition.

The final sprint (the finish line is somewhere off in the distance here . . . )

Prepare for boredom, but don’t drown it out

On this race I learned that monotony and boredom can be an issue for me on really long runs, especially when running by myself.   When preparing for the race, I loaded up on podcasts and audiobooks, and decided to listen to something from around checkpoint 2 – thinking that it would be good to stay distracted and keep my mind occupied during a long, long event.  The truth was that the stuff I was listening to made me distracted and bored, and made me feel disconnected from the race – so in future I’m going to use my iPod a lot less.

English quaintness everywhere

Be humble

100km is a huge stretch, and you never know what’s going to happen.  Old injuries can flare up, new injuries can appear, heat, exhaustion and just about anything else can get the better of you – so never turn up to one of these with an assumption as to how you are going to perform.  It’s nice to get a good time, but mentally prepare yourself for the what-if of a DNF.  Staying within my limits is what got me to the finish line comfortably, and humbly, pleased I was lucky enough to get through the race without major issues.

Finally! The finish line . . .

Your first 100km event is always going to be a mammoth undertaking, but mental preparation and having a strategy in place is key for keeping you in the game.

Check out our Essential Guide to Running Your First 100km, with a training plan →

Final Results
Final Results

By Thomas Watson

Thomas Watson

Thomas Watson

Thomas Watson is an ultra-runner, UESCA-certified running coach, and the founder of His work has been featured in Runner's World,, MapMyRun, and many other running publications. He likes running interesting races and good beer. More at his bio.

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