WHAT IT’S LIKE TO RUN YOUR FIRST 100 MILER

11 lessons I learned taking on the RR Castle to Castle 100

Runners are often asked why they run. Some additional exclamation marks can be added when the question is, ‘Why would you take on a 100-mile run?!!’ 

Well, it is a good question, in fairness! I will attempt to answer that here and share my experience of what it’s like to run your first 100 miler.  

So, how far really is 100 miles, further than the usual Ultra running distance?  I hear you ask. Let’s add some scale: 

·        3.8 marathons 

·        32+ park runs 

·        161.1km’s 

·        403 laps of an athletics track 

·        Equivalent of running from London to Brighton, then back again! 

In short, there is no short—it’s a long way! Now that you have an idea of the undertaking, let’s get into the experience of taking on the Rat Race Castle to Castle 100 as your first 100-miler. 

The stage was set. In the shadow of Bamburgh Castle, there was a countdown from 3, and then we took the first of 200,000 steps that would be required to cover the 100-mile run distance to Edinburgh Castle. The first-ever Rat Race Castle to Castle 100 miler was underway! 

You’ve likely heard about the stages of grief. I think it’s easiest recounting the journey to the start line and along this 100-mile run in similar stages...! 

Denial – Am I really going to attempt a 100 miler? Am I mad?  

These were the dominant thoughts after hesitantly saying yes to a nonchalant email invite asking us to either run or crew this Test Pilot event. After giving the nod to run, every time the event came to my mind, it was with an accompanying thought telling myself, ‘It won’t actually happen; it’ll be postponed’ or ‘You won’t really need to do it’. Spoiler: it did actually happen! 

Lesson: Commit to it fully. Embrace the challenge, move past the denial phase early and get going with your training.  

Fear – Marathons are hard. How am I going to manage 4 of them back-to-back?  

When I talked myself into the possibility that this may be happening, the next stage was fear. Fear of pain. Fear of the distance. Fear of the unknown. ‘This is probably going to hurt… a lot’. I was anxious of the reality of it. I think this is normal, and if you aren’t anxious, please refer back to the scale of it and double-check you realise what you’ve signed up to! 

Lesson: Fear is a natural body response when we’re trying to protect ourselves. Channel that energy positively to help fuel your preparations.  

Excitement – Growth comes outside the comfort zone.  

After setting the denial aside, things get easier. If it’s going to happen, there’s no point being fearful. Time to be practical, and you may as well find reason to be excited. That is in abundant supply here. Firstly, it’s renowned for being a beautiful stretch of Northumberland Coast that I’ve never visited before. Experiencing new places on my own two feet is one of my biggest motivators for running. Secondly, the furthest I’ve run before is 100km, so this is a massive step up. With that comes a lot of excitement for growth and achievement. I tried to hold onto this feeling.  

Lesson: Remember, you’ve signed up for this in your own free time. Find the positives that excite you in your own journey and hold onto those.  

Worry – Keeping the demons at bay. 

Even past the initial denial and fear, worries still creep in. ‘Surely there’s no way I can actually do this?’ was a nagging voice that needed slaying. This was accompanied by the normal worries about my body giving up or DNF’ing through bad luck or lack of prep. Both were very possible, as prep had been lacking. I relied on my ultra running distance experience as I had done little specific training for the event. The more you train & prepare, the fewer these worries should be.  

Lesson: Start training and preparing now. The earlier you start, the more confident you will feel throughout your buildup and at the 100-mile start line.  

Acceptance – The easiest part, in many ways, is toeing the line.  

Signing up, training and managing your mindset can be mentally taxing in the build-up. Once we finally arrived in Bamburgh, it was a big relief. There’s still some usual last-minute nerves and excitement, but there’s no real point worrying about anything by then, as it’s just too late. The start line brings a welcome sense of relief that you can start putting one foot in front of the other and just get on with it. What will be will be! 

Lesson: Look forward to and cherish the start-line moment. Getting there is a huge achievement in itself. Try to relax on the day; all the work is done by that point.  

Tiredness – Well, what else would you expect?  

Picture this. You pull an all-nighter and cram a month of work into 24 hours. No, I’m not talking about my Uni exams. This is essentially what this event was in some ways. My training volume had been low going into this, and I only managed a few short runs a week, most weeks in the build-up, including a parkrun and one or two easy runs. It’s not an exaggeration, therefore, to say that this event was around 4 weeks of normal running volume crammed into 1 day. Get comfortable with tiredness. It’s likely to hit you like a wall when the sun goes down. The support around you will help you through this.  

Lesson: Expect tough moments. This is a 100-mile run, after all. Mentally prepare for times you may hurt or be low on energy and have coping mechanisms in place.  

Euphoria – Time for the Runners High. 

You’ve likely heard of this before from ultra running distance competitors. Your pace is dialled in, your stride is easy, the wind is in your hair, the endorphins are flowing, and things feel just right. This is the ‘Runners High’. It is an amazing feeling, and you don’t get it every time you run. The beautiful thing about a 100-mile run is that you have such a long time for your body to get into that magical zone and for this feeling to come to you. It’s another solid answer to ‘why would you do a 100-mile run?!’ Being in beautiful surroundings makes it much easier to obtain this elusive feeling, and the RR 100 miler brings this to you by picking a stunning route which you get to experience from sunset to sunrise.  

Lesson: Embrace the highs! 

Elation – On the cusp of victory. 

With this being such a long way, it’s normal to break it down into chunks. Key milestones along my journey were every 10 miles, 50 km, halfway, 100 km, 1 marathon to go, and then a countdown from 130, 140, and 150 kms. Somewhere between crossing the 100km mark and passing 120km, with less than a marathon to go, I felt like I could do this. It wasn’t in the bag yet – there was still a long way to go, but in the scheme of things, a marathon did not seem so far. Even on tired body and mind, the balance was in my favour. We were 3 quarters done and counting down. I just needed to keep digging in.  

Lesson: Plan your own milestones and feel the positive energy as you tick each of them off.  

Pride – If you can do this, you can do anything. 

One of many beautiful landmarks along this route is Arthurs Seat. This iconic 250m hill is a landmark feature of the Edinburgh skyline. It’s conveniently located around 1 mile away from Edinburgh Castle, and so it serves as a distance marker for this event. I remember first noticing it about 15 – 20km before the finish line, and it’s such a beacon of hope. You really feel that you are in the last stretch when you lay eyes on Arthur's Seat. NB., you’ll be pleased to know, however tempted the event organisers were to put the summit in as a final test and viewpoint, we fought that urge. You don’t need to run up it so you can breathe a sigh of relief! 

Lesson: Be proud of your achievements regardless of how far you get. Toeing the line is a huge accomplishment. Also, look out for Arthur's Seat—it’s a huge relief! 

Emotion – I’m not crying, you’re crying.

On finally reaching the finish line, it’s an odd feeling. For most people, this is the achievement of a lifetime. There is relief, joy, disbelief, gratitude, and so much more whizzing around your tired mind. Sleep deprivation compounds this strange mix of emotion; so don’t be surprised if you end up with sand in your eyes, ahem.  

Lesson: Let the emotions flow.  

Suprise – Am I really considering doing this all again?  

In general, I expected the roller coaster of emotions listed thus far. One thing I did not expect was to entertain the thought of doing another one. I’ve always wanted to do a 100 miler. Just one. Up until this point, I had done everything from 1-mile races on the track to road marathons and multi-day trail ultra-marathons. A 100-mile run continuous was a big challenge that I needed to tick off at some point to be a well-rounded runner, or so I had told myself. This was to be my one and my only reason being that I thought it would be an extended form of torture that was purely ‘type 2 fun’. I.E., not actually fun at all, but looked back on with fond memories and retrospective enjoyment after it was done. Truth is, it wasn’t so bad. A conservatively paced first half meant I came into the second half feeling strong. There were some tough moments, but whilst I thought I might enjoy the first 15-20 miles and have to grit my teeth for the rest, I kind of enjoyed it all. The positives and the highs outweigh any tough sections at least 10-fold, and it’s now one of my biggest and proudest achievements from 15+ years running.  

Lesson: Be warned, this might not be your last 100 miler! 

So, those are some of my learnings, I hope they help you. In July 2025, around 700 of you will toe the line to experience these yourselves. We can’t wait to share this belter of a route with you and to support you along your own journey. If, like me, you find yourself thinking about doing it all again, you’re in fortune. The RR100 will be going on tour, and there will be a new date and location announced for 2026. So, if you get to Edinburgh and find you have a new addiction, fear not. Keep those eyes peeled for the next stop on the tour! 

Right, that’s all for now. Expect more to follow on fuelling, training and more. Until then, over to you for 2025 – see you on the start line!