“Just more of the same, but longer.” That’s how most people think about stepping up from 100 miles to 200. It’s not true. The extra hundred miles doesn’t just add more hours onto the clock; it turns the whole event into something different. Suddenly sleep isn’t something you’re avoiding, it’s something you must actively manage. And your feet, your gut, your head, all of it starts operating somewhere a 100-miler never takes you.

So, as I’m preparing for the GMR200 by GB ULTRAS, here’s what I’d want anyone lining up for their first 200 miler to know, drawn from everything the 100-mile distance and then another 100 miles on top of it has taught me and from digging into exactly what that extra hundred miles asks of you.

1. It’s the lack of sleep that breaks you, not the mileage

Most runners can battle their way through 100 miles on willpower and grit alone. Not at 200. You’re looking at 60, 70, even 80-plus hours without proper sleep, and that’s not a fitness issue, it’s a brain issue. Decisions get slower, moods swing harder and even your sense of reality stops being trustworthy. Sleep strategy deserves the same respect you’d give your training block.

2. Expect your feet to change shape mid-race

Hours on your feet at that scale means swelling and even aches and pains you’ve never experienced, there’s no getting around it. Shoes that were perfect at the start line can feel a size too tight by hour 30. Don’t leave yourself with just one option. A half-size up, a wider fit, maybe a completely different pair for later, this isn’t overkill, it’s just what most finishers do.

3. Past 36–40 hours awake, hallucinations are normal

Shadows start looking like animals. Rocks start looking like people. First time it happens it’s unsettling, but it happens to almost everyone who goes this long without sleep. Knowing it’s coming strips away a lot of the fear. It’s your body doing exactly what sleep-deprived bodies do, not a sign something’s wrong.

4. A smaller, sharper crew beats a bigger one

More helpers sounds like a safety net, but more people often just means more mixed signals. One person who really knows your race plan, your nutrition, you in general and can stay level-headed when you can’t, that will carry you further than five kind-hearted people all working off different information.

5. Nutrition has to evolve once real sleep deprivation kicks in

What kept you fuelled at hour 20 might not touch the sides by hour 50. Losing sleep changes your appetite and what your stomach can actually handle. Go in expecting your fuelling strategy to shift through the race, rather than clinging to whatever worked in training or in shorter events.

6. Blisters that would’ve ended a 100 become something you push through

At 100 miles, a bad blister can be race over. At 200, you end up managing pain that would’ve been a DNF trigger at a shorter distance, because stopping means walking away with 100-plus miles still left. Taping, draining, dressing wounds on the move, these stop being optional skills and become essential ones. I’ve witnessed a friend nearly lose a little toe or worse on a 200 miler, if it wasn’t for his taping and dressing skills. And yes, he made it to the finish line.

7. The real low point is the middle, not the finish

counter-intuitive, but true. It’s not the final push that tends to break people. It’s the middle, where the finish line still feels impossibly far off but the fatigue and sleep debt are already deep. Going in knowing that low is coming and that it does pass, makes it a lot easier to get through.

8. A short nap can outperform stubbornly pushing on

A sharp 10–20 minute nap can do more for your head and your mood than another hour of half-asleep shuffling. Runners who build planned sleep breaks into their race strategy, instead of treating any stop as giving up, often finish faster overall, not slower. Even the forest floor at 3am looks comfortable when you’re deep into sleep deprivation. Set your alarm, drop and curl up.

9. After hour 30, throw the pace plan out

Spreadsheets and pacing charts earn their keep in the first third of the race. After that, your real-time state, sleep debt, conditions, how your body actually feels, matters far more than any number worked out weeks earlier. Learning to adjust hour by hour instead of chasing a plan is its own skill. Plan for the first 24 hours and leave everything after that flexible.

10. It’s stubbornness that finishes 200s, not raw ability

The most talented runner on the start line rarely wins a 200-miler. It’s finished by whoever keeps making forward progress, however slowly, for however long it takes. Patience, stubbornness and the ability to keep thinking clearly while wrecked matter more than fitness ever will. It’s a whole different ball game, I’ve lined up with some incredibly talented runners, only to see them DNF in the first 24 hours because of underestimating some of things I’ve talked about above.

None of this replaces the training miles, but understanding what actually breaks people at 200 miles (sleep, feet, eat, not distance) changes how you prepare, how you crew, and how you race. Focus on the process and the outcome is inevitable.