One Month to Go to the Arc of Attrition by UTMB: What You Should Be Doing Now

Pembrokeshire Coast Path - not quite the Arc of Attrition, but a coastal challenge in its own right

The Arc of Attrition by UTMB races are just around the corner, with exactly one month to go until the start of the 100-mile race on the Cornish coast. If you’ve been training to complete 50 or 100 miles, the looming challenge can feel quite daunting, especially when you’re juggling end-of-year festivities, family and friends, work, pets, and who knows what else! But there’s a lot you can gain in these last few weeks, if you approach them strategically and with the right balance. 

We caught up with Arc veterans Sanna Duthie (fifth at the 2023 100-miler) and Poppy Collingwood (50-miler winner in 2024 and runner-up in 2025), as well as Coaches Doug Stewart and Ronnie Staton, to get their final tips and advice.

The One-Month Countdown: Don’t Panic

As the race draws near, it’s always tempting to think you could do more and doubts tend to creep in. But remember, you can gain more in niggles or injuries than you can in fitness at this stage. The bigger wins with one month to go will be in logistics, planning, and visualisation. And don’t underestimate the power of rest: use the end of year holidays to recharge your batteries while you enjoy time with your loved ones - this is when you build feel-good memories you can draw upon when the trails get tough!

Arc of Attrition 100-mile race top 5 finisher, Sanna Duthie, reminds runners of this, too. “Trust your training up to now and don’t worry about what everyone else is doing,” Sanna says. It’s too tempting to compare your mileage, especially as the Arc takes place so soon after year-end when people post all their Strava achievements. But only you know what is right for you and your race goals.

Plus, don’t forget your life commitments! Another key tip from Sanna is to manage the overwhelm by being conscious of just how much you can do as the race approaches. You’re likely to be feeling like you’re being pulled in every direction right now, so remember running is supposed to be fun and let it take its place in the rest of your life, not lead it. 

Sanna doing her hill training

How Best to Spend the Next Four Weeks 

So, what can you do right now to feel better prepared and ensure your Arc of Attrition races go as well as they can? Here’s a countdown checklist. 

Enjoy Christmas & New Year’s Festivities

First off, don’t feel guilty for taking time off and spending it with loved ones over Christmas and the end of the year. It’s an important part of life and rest is training, too. In fact, this is a good test of you trusting the process. Coach Doug says, “Don't try and ramp up training in the final month, this is likely more of a risk than a benefit. So stick to your plan and have confidence in your training.”

The only thing you should maybe consider dialling back on is the very late nights. Sleep is an important part of recovery and being well rested will also help during the race. We’ll come back to this below.

Finalise the Training

When it comes to running, focus quality over quantity, protecting the fitness you’ve built up. “Every run should have a purpose, but shouldn’t leave you feeling extra tired,” says Coach Ronnie. “Dial back the long run in the closing weeks. It takes months to build significant endurance gains - that ship has sailed.”

You could still take advantage of some time off to get some specific training in, while dialling down on intensity. Previous Arc 50-mile winner and this year’s runner-up, Poppy Collingwood, remembers finding a quick recce extremely beneficial if you are anywhere near the Cornish coast. The section from Sennen to St Ives (90 km / 56 miles into the 100-miler, and the first part of the 50-miler) “is relentless, every headland feels the same… it sometimes feels like the end is never coming.” If you’ve seen it, you’ll know what’s coming - or simply remember these words! A good trick to substitute a recce is to watch people’s race videos on YouTube and get an idea of some of the terrain you’ll be dealing with.

Another tip from Poppy is to get some stairs in. “Despite the hills not being that long, some are punchy. Doing some step-ups at the end of an easy run prepared me for those steps, especially at the end of the race when my legs were tired.”

Finally, Coach Doug advises all his runners to load up their vests with the full race kit on the final long runs. You may not need it for that last 1-2 hour outing, but it gets you used to the weight and it’s an opportunity to double check for any hot spots or rubbing, so you can prepare accordingly on race day.

Last Call for Nutrition Planning

You should have practiced your nutrition and hydration during your long runs by now, but here are a few last-minute tips if you’re still having doubts, courtesy of Coach Doug:

• Consider the route and time you’ll spend to get to your drop bag or crew (remember there is no crewing on the 50-miler!), and think of what you may want to top up with from the aid stations. Check the race website to see what will be on offer, and try this food on your last long runs so you’re not unfamiliar with it.

• After 10+ hours on your feet, your stomach may not want any more of your favourite gels or bars. But it’s hard to know now what you’ll want when the going gets tough. A good tip for figuring this out is to end your long run at a local convenience store and walk around, seeing what is calling to you. This will be the sort of food you’ll want in the last miles - buy some and try it on your next run, whether it’s crisps, pickles, or a mince pie (stock up on those discounted ones just after Christmas!).

• Final feel-good tip: put a treat in your drop bag (or crew bag on the 100 miles). That Snickers bar will never taste so good as when you’re hours into your ultra, windswept and sore… not to mention the happy memories brought back by your favourite crisps flavour or the bacon butty your partner made that morning for you!

 

Make the Most of Tapering

Tapering is tricky, especially for those of us who start to feel worried they’re not doing enough. Coach Ronnie suggests avoiding a long lull on the sofa “carb loading” - no one feels good from it. Instead, keep dialing down the intensity and the length of your runs, while also doing light mobility exercises. Avoid heavy strength work or super intense runs.

If you can, increase sleep duration gradually in the last couple of weeks. Adding on 15 minutes at a time, you can increase sleep by an hour and you’ll feel fresher and better rested come race day. This should also help you cope better with the lack of sleep during the run.

Finally, use the extra time to prepare course knowledge, prepare your pacing and your crew if you’ll have one. 

 

Prepare the Logistics

Now is the time to start visualising the course, thinking of your pacing plans and preparing your “what-if’s” or “if-then” lists (if you haven’t already!). By this point, you should have already tested all your kit in training and prepared and tested a fueling strategy. If you haven’t, you still have one or two long runs to do it, but don’t decide you’ll switch from your trusted race vest to the one your cousin got you for Christmas, just for sentimental bonus points. If you end up chafing or not fitting enough kit on race day, they’re not there to run in your place!

When it comes to pacing, even if you’ve not done the race before, you can get a rough idea of what you should aim for by using your UTMB Index (if you have one) and previous years’ results. Coach Doug uses this method: look at the previous finishers’ UTMB Score, which will be listed near their finish time. Compare this to your index to get a rough idea if that’s an achievable time for you or not. You can then go onto the Live UTMB page from last year, find the person whose time you want to emulate, and see their splits. This is obviously not fail-proof and factors like the weather can change things, but at least you’ll have a rough plan to start with. It’s also a good way to work out just how long some sections in between aid stations are likely to take (note some are quite long, so plan to take extra food and water). 

And, if you haven’t already, book your accommodation and plan your travel. You want to reduce stress and uncertainties in the last weeks before the race, so make sure you also have a clear plan of what’s going to happen in the final days:

• When is registration and kit check?

• How are you getting to the start?

• What are you going to eat the day before and on the morning of the race? Will you cook or bring food with you?

• When are you packing your race vest?

• When are you briefing your crew and handing them your kit and food (for the 100 miles)?

Working this out ahead of time and writing it all down can take a huge load off your mind and reduce unnecessary last-minute anxiety. Coach Doug also warns: “Always build in some contingency in case things take longer than you expect… they usually do!”

Working through race vest essentials

Enjoying Race Day

The best laid plans can and will go wrong during an ultra. That’s part of the beauty of it. The longer you go, the more factors come into play, but planning and having a rough idea of timings, aid stations etc, will all make you feel better on the start line. Then remember that race day really is a celebration of your training and hard work. As Coach Ronnie puts it: “Remember, it’s supposed to be fun and I’m pretty confident you paid to do it rather than it being your job. It’s an adventure, so don’t pin your self worth on it. Embrace the challenge, give it full beans and accept where you land.”

The Cornish coast is both beautiful and brutal. You’ll be there for the challenge, but also for the enjoyment. Sanna says: “Do it with a smile, enjoy the views, meeting new people, and completing something epic.”

Remember: no one ever is as fit as “they’d want to be.” But the goal in this final stretch is freshness ahead of the race and enjoyment on the day. And don’t forget to smile at the photographers so you can show off your brilliant photos for the rest of the year!

 

Want to know more about how to train for an ultra and dial in those checklists and countdowns?

Our Guide “How to run an ultra” has it all. Go through some of the modules here or purchase the entire guide here.