How To Run 100 Miles: Training Plan For The Mind & Body!

Man in sports gear running on a motorway.
Roughly the 6th mile of 123, a long road ahead!

Are you a keen runner who wants to know how to run 100 miles and still live to tell the story?

After completing this challenge for the first time in the brutal Thai sun I decided to put together the ultimate guide on how to run 100 miles for those wanting this massive running milestone in their locker.

This post will focus on physical and intense mental preparation in the days that lead up to the race so that you can limp home to glory after running 100 miles.

How To Run 100 Miles: The Raw Truth

Running 100 miles is going to hurt. You will ache in some ungodly areas (my bumhole took one hell of a beating) and your mind will go to some very dark places if you let it.

Then there are the unplanned bathroom breaks, the vomiting, the paradoxical lack of desire to eat when you really need to refuel and moments of crippling self-doubt when the voice in your head becomes your loudest and biggest critic.

I hallucinated when I ran my first 100 miles ultramarathon and I slept-ran… a phenomenon where my body continued moving forward but I was somehow having micro naps, full of vivid and cerebral ‘Requiem For a Dream’ types of delusions while wandering out into oncoming lorries.

In the past, I have climbed some difficult mountains and run ultras where others who are way more talented than me have failed because they were too cocky.

They wanted all the plaudits but they thought the accolade would be handed to them on a silver platter and their arrogance led to their disappointment.

Don’t be that person and give running 100 miles all the respect that it deserves by fully preparing for the big day.

Mindset Advice For Running 100 Miles

You should prepare and train your mind just as seriously as your body for running 100 miles. I used to roll my eyes like a sassy member of ‘Mean Girls’ at phrases like “completing an ultra is more about the mind than the body” and pass it off as a cliché.

I was wrong.

It’s not a platitude, statements like this are absolutely correct when it comes to running ultras. 

While it’s unquestionably true that you need your body to be in prime condition to go through the stress of running 100 miles, you need to bulletproof your mind for when that inner bitch starts bullying you.

This guide has a physical training plan for a 100 miler. But first, it is imperative to focus on how what ultramarathon legend David Goggins would say, “stay hard” for the upcoming training and most importantly when your body is in discomfort during the big day.

Have A Strong Enough Reason “Why”

I often offer this as the number one piece of advice to anyone who is struggling with motivation for goal-setting whether it’s reasons to leave your hometown, getting to the gym, or running a seemingly insane distance. It’s certainly important to know your reason why you want to run 100 miles. There will be times when your mind hijacks you during the run and asks you “What’s the point in all of this?”

Your answer will need to be quick and concise to keep the doubt beast at bay as you will be mentally and physically exhausted and very suggestible.

Spend an hour or so writing down what your answer may be, or take a few weeks and look out for anything that pops up naturally.

We ran our 100 miles ultra for a local charity who were desperately in need of finances. I used this as fuel, but to be honest, it wasn’t completely altruistic as I hate failing at challenges so this was an added reason why running 100 miles had to happen.

For me throwing in the towel when there is still even a little bit of fight left in me is simply unforgivable. 

This is a very ego-based reason why and that’s totally fine because it is YOUR reason why and it’s important to YOU, something that galvanises you to rise like a phoenix from the ashes when you are beaten to your knees.

If your reason why is something lovely and wholesome like making your partner or family proud, funding a charity close to your heart, or even just a happy memory then use it if it works for you as a strong enough reason why when the chips are down.

Don’t listen to any dipshit pseudo-psychoanalysis from others who just don’t get why you’d want to run 100 miles. Most people are projecting their own insecurities and fears and once you notice that it’s much easier to not take their pessimism so personally.

Dip Into Your Cookie Jar

From the safety of your own couch, watching an individual on TV take on this task is fun and you’re likely to get a dopamine rush just watching them on their path to success. It’s hard to tap into the places that your mind will go to when you feel broken and can’t take anymore.

Something of great help to me during the most hellish parts of my run was advice from that madman again, Mr David Goggins. Take a few moments to hear his “cookie jar” method for when the chips are down:

Too long, didn’t watch?

It’s ok Mr Goggins isn’t for everyone, however, if you genuinely get upset about someone saying a couple of naughty words then I doubt that you will be tough enough to run 100 miles.

A 100 mile run does not care about your precious feelings.

The Cookie Jar Method is when you remember a handful of achievements in your life where you almost failed, but you succeeded because you knuckled down and persevered through the doubt and pain.

Imagine an empty cookie jar and that each of these achievements is a cookie that you are storing as a memory. 

When you are suffering serious doubt and pain while running 100 miles you should dip into your cookie jar and grab a cookie (memory of past success) as a mental reserve to remind you of the bouncebackability that you have deep within you, in order to crush that doubt that’s trying to make you quit.

This might sound a little cheesy to some people, but what’s the alternative? To crumble? To beat yourself up mentally when you’re already physically beating the shit out of yourself?

Running 100 miles is hard, there is no point in making it harder by spiritually genuflecting to negativity.

Work On Your Internal Dialogue 

On that note, let’s talk about making your mind impenetrable to any negative “you can’t do it, you’re not good enough” gremlins that rares their ugly head during times of distress with these mind-strengthening methods.

  • Recognise your negative thoughts. In order to tackle a problem, you may first become aware of it at the root. Listen out for negative self-talk and look for a pattern.
  • Laugh it off. Instantly, or sooner rather than later. React to it like how you’d treat a petulant child that is throwing a tantrum, dismiss it as ridiculous and don’t tap into that energy.
  • Treat yourself like a loved one. Would you talk to a partner, parent, friend or child in the toxic way that you talk to yourself? Hopefully, the answer is no, so treat yourself with the same level of dignity. Your inner dialogue is incredibly powerful.
  • Just accept that some won’t “get” it. It can be disappointing when you share your running 100 miles goal and someone close to you makes disparaging comments. Just accept that we look like a raving loony to most people because we set the bar so high, maybe they’re projecting or maybe they meant no harm. Forgive them and don’t let their words affect you. Better still, make proving them your “reason why” if that works for your personality type.
  • Celebrate segmented milestones. During your 100 miles race, focus on getting to the next 10 miles mark and when you get more tired focus on doing it in segments of 5 miles, do the same for training so that you are mentally ready on the big day. Speaking of which… When you achieve each milestone, it’s important to reward yourself. How about customizing a running medal when you complete a training phase or reach a certain distance? You can easily customize medals for any occasion at!

Am I Ready To Run A 100 Miler?

The optimal experience that you need to run a fast 100 miler is to have run at least one ultra previously (and recently) and be willing to put in 8-14 hours of training for over 6 months. Read my comprehensive post: how long does it take to run 100 miles if you want a detailed point of reference about what makes an impressive “average” time for running 100 miles.

However, if you want to run a 100 miles ultramarathon as soon as possible and simply get over the finish line, you may be very surprised by how quickly you can be ultra-ready. 

I am not a proponent of half-assing things, but if for whatever reasons you have you are itching to make the century club sooner rather than later, then it is possible to be ready within 12 weeks for your first 100 miles ultramarathon.

This was admittedly not my first rodeo in terms of running a crazy ultra. In 2019 I completed 6 marathons in 6 days in the Sahara Desert, often referred to as “The Toughest Footrace on Earth.” (You can read my Marathon des Sables review here).

Other than that, I’m just a regular bloke and certainly not an advanced ultra-athlete and at the start of my training, I was not ultra-ready.

A lot of online publications seemed to suggest that you need to train for a year to be eligible to run 100 miles and I would not so politely say… bollocks to that!

I only had 3 months to train for my 100 miles ultramarathon (plus another 23 miles.) I was basically in injury rehab for about half a year before that and the only exercise I was doing was bodyweight callisthenics during a strict Covid-19 lockdown, with my only cardio regime being leaving my sofa during Only Fools and Horses episodes to have a wee or a cuppa.

I respectfully disagree with these online resources for 2 primary reasons:

  1. I have pushed my body and mind over the years to the absolute limit, and know that we are capable of so much more than we believe.
  2. Most of those resources are speaking to actual elite athletes who are going for a specific time, not weekend warriors, have-a-go heroes like myself.

With all that being said, you have to factor in your personal lifestyle and current condition. I know this is a well-beaten dead horse, but a lot of this really is mind over matter (and blisters).

Strength Training For Running 100 Miles

Oh, how I wish I listened before my first ultra when I was told the benefits of strength training for ultramarathon training.

I guess I was struggling with a bit of cognitive dissonance as I never really particularly enjoyed lifting weights and have always had more of a buzz from running. 

However, the difference for me when I chose to strength train before my second ultramarathon compared to my first when I didn’t was night and day.

If you’re anything like me, you may have groaned at this part and thought to yourself; “where the hell will I find the time to add strength training to my already busy plan?”

I feel your pain, when you’re already putting in serious running hours it seems a thankless task to squeeze in resistance training on top of the grind you’re already putting in, but I promise you that extra effort reaps a great reward.

The key is to keep it simple.

You don’t have to put your tired, weary legs through heavy barbell squats and excessive Serena Williams-grunting deadlifts. 

If you don’t have the time to hit the gym on top of your running training and can “only” do callisthenics-based exercise from home, then that’s brilliant.

Bodyweight training is fantastic. In true runner’s spirit, repeat after me as you smear your gooch-saving Vaseline war paint over your face; “my body IS a gym!”

Aim for 3-full body sessions per week of 30 minutes to an hour of bodyweight training, feel free to add these usual suspects’ resistance exercises to your 100 mile training plan:

I would argue that bodyweight resistance training is better as most of these force you to do high reps (15-25) when using less weight (only your body), so it builds endurance while keeping your ligaments strong and therefore preventing injury without all that heavy load on your tired-from-running body.

I felt a significant difference in attacking steep hills for my 100 miles ultra compared to my first ultra when all I did was train cardio and no strength training at all.

What Should My Weekly Mileage Be in a 100-Mile Training Plan?

For optimal training for a 100-mile run, you should build up to 60 to 70 miles per week before tapering. If you are short on time and want to run the 100 miles sooner, you can get away with 40-60 weekly mileage at peak training but don’t expect to be anywhere near this goal if you are only running 5 kilometres every day.

I have also run a last-minute 100-kilometre ultramarathon with 20-30 weekly mileage at peak.

As long as you are not carrying any injuries, you can get away with less weekly mileage so long as you have adequate rest and train other areas of your body accordingly, but more is certainly better if you have time (and patience) on your side.

Periodisation Training For A 100 Mile Training Plan

Periodisation training is a structured training plan in which the individual progressively overloads their volume over a period of time before hitting a peak window where they are going to an intense level. Then, they taper off their efforts (do less progressively) in due course for the big day.

That was quite a mouthful, right?

There are actually more layers to it, but I don’t want to make this any more complicated than it needs to be. I set out from the get-go with the goal of this being an everyman’s 100 mile training plan, so let’s try that again in Layman’s terms:

  1. At the start of my training, I ran a certain amount of miles every day for 5 days per week.
  2. Next week I increased my miles and ran more every training day that week.
  3. Several weeks later, I was running a large number of miles every training day, which I referred to as “Peak Week,” as it was my planned most intense week.
  4. The week after Peak Week I started subtracting my miles from that total.
  5. I subtracted more miles each week until I got to 4 days before the run. (Also known as tapering).

I am going to assume those reading this aren’t going to try and run a 100 miles ultramarathon as last minute as 3 months, but the beauty of periodisation planning is you can customise it to your own timeline. (pssst, this is another reminder that you can run 100 miles sooner rather than later if you have your own reasons!)

Below is my personal periodisation training plan for a 100 miles race over a 12-week period. All you need to do is copy the system on an Excel sheet or even with a good old-fashioned pen and paper… whatever floats your boat.

100 Mile Ultramarathon Training Plan (Customise As You Wish!)

Here is your first-timer’s free 100 mile training plan, the one that got me over the finish line for my first 100 mile ultra (it was actually 123 miles, sorry to be pedantic, but it’s a nice extra reminder of what we can achieve if we prepare our minds and body). 

Get the kettle on and prepare to play around with your own plan until you’re happy with it as it took me a few goes. All numbers are in miles, not kilometres. 

You will see that I took weekends off and went hard Monday-Friday. My theory was that I needed to get my body primed for running exhausted and also I like to have my weekends for rest and recuperation.

You can easily swap the days that you prefer to rest. To be honest I think it’s much smarter to have a day’s rest during the week and still run on weekends, which will probably fit in better with most people’s schedules.

I left my ego behind and did not run these miles at a fast pace, I simply got the assigned amount of miles for each day done, to achieve the most important priority of getting a high volume of miles on my legs and body during training.

Here goes:

100 Miles Ultramarathon Plan
Edit as you wish 🙂

Additional Training For A 100 Mile Ultra:

The above plan plus strength training might seem overwhelming especially when I am mentioning extras in this 100 mile training plan. Don’t worry, most of what I am going to mention here can be done alongside your running plan above; it’s about training smart as well as hard.

Mobility work

A lot of the exercises listed above in strength training for a 100 miles race are essentially mobility work too. Strength training and mobility go hand in hand, and “mobility” has become a bit of an overused buzzword over time.

Just like with the strength training, stick to the basics and add any extra ultrarunner-friendly mobility exercises to the end of your bodyweight strength exercises for extra range of motion, more overall power and coordination in your runs.

Running Hills

Make sure 1 or 2 of your weekly runs contain running up rather big and disgusting hills! Ultramarathon race organisers seem to have a sick sense of humour, adding the steepest terrain that seems to pop up when you’re already exhausted.

The first priority in your 100-mile training plan is getting miles on your legs. The next one is priming them for climbing any arduous hills. A long race is realistically never perfectly flat, so train for those slopes.

Walk Whenever Possible

If you are not an elite runner, you are likely to walk some of the 100-mile ultramarathons, and there’s absolutely no shame in that. I’ve seen sub-19-minute 5k runners curl their lips at this idea, most of them never wanting to run an ultra or understanding what it takes to get through one.

So ditch the lift and walk up the stairs, be honest with yourself if you’re being lazy taking the car when you could walk and go for more strolls during your work break – do all you can to get those extra steps in to prime your body to be the very best it can be for your 100 miles war.

Active Rest

Active rest doesn’t mean marathoning your favourite Netflix show, it’s more about participating in another form of (easy-going) exercise that you find fun but don’t go gung-ho and burn yourself out.

For example, on my day of active rest, I’d walk around a beautiful lake, go to beginner’s yoga or join my friends for a few hours of badminton. This gave my body the chance to heal while increasing blood flow to my sore muscles.


There’s nothing wrong with the aforementioned Netflix binge, if you feel like you need it while sticking to your training plan – then take it and feel zero guilt.

You deserve it after putting all those hours of work in!

The most imperative factor in your crazy ultra-training plan is getting sufficient sleep. The chances are you’ll be exhausted and ready for your bed most nights, but if like me you still struggle to get shut-eye, take 200-300 mg magnesium threonate a few hours before you go to bed. It will help you relax and it also helps to prevent your depleted muscles from cramping.

7 Food Tips To Help You Run 100 Miles

When running a marathon (or even a half marathon) your body is burning off an unnatural amount of calories.

During the half marathon (on a very hot day) at The Great North Run, I got away with only needing 2 energy gels to get the job done, however with the extreme marathons in the Sahara Desert I had to constantly feed myself.

So you can only imagine that whilst running 100 miles, which is just shy of 4 marathons in 1 go; refuelling is of paramount importance. Thanks to the desert run, I made a lot of mistakes when it comes to food and I hope that these 7 tips will serve you as well as they did me.

1. Try Out Your Race Food on Training Days

Firstly, make sure that the meal immediately before the run sits well in your stomach. Then do a trial run (literally while running) with your snacks, as you will find that some snacks digest better than others do.

I found out during Marathon des Sables that those very popular carb gels give me diarrhoea, and newly-prepared me found out that pitted dates digested much superior to the gels. It’s better to find out way before your big day than it is mid-ultra.

2. Carbs Are King

During the late 90s, perfectly healthy dietary fats got an unfairly hard time in the media. This time around carbs are getting unjustly bashed.

All carbs are not created equal, but the beauty of running an ultra is you can smash fast-acting carbs such as fruits, gels, glucose drinks and white rice during training and your race. Just avoid overloading too much on fibrous carbs such as lentils and beans directly before or during training as you could run into gastrointestinal distress. (However, I ate them after training and felt fine!)

3. Don’t Forget About The Other Macronutrients!

Carbs are still the go-to macronutrient for nutters like us who do anything endurance-based, but when you are in your rest window your body is also craving protein to fix your broken muscles and repair your body, so make sure to have a 30-50 grams serving of protein at every meal and also consider supplements that regulate protein synthesis.

Healthy fats are vital for healthy hormone production, so make sure you have all 3 macros on your plate when you’re post-run. A typical meal for me after a long training run was 2 cups of lentils in a marinara sauce with leafy greens, two tablespoons of hemp seeds and half an avocado.

4. Pre-Race Meal Is The Night Before Too

The food that you eat the night before the race is as important as what you eat for breakfast. There is a reason why ‘pasta parties’ are popular the day before big events, the carbs are banking in your body for the big day.

However, don’t go wild and overeat gigantic plates of spaghetti as you may have trouble sleeping and a good night’s sleep will make all the difference to your big day.

5. Plan Your Fuelling Strategies

Do you feel better eating every 5 miles or every 1 hour? Maybe you’re more of a caffeine kick/dates/gel/Bloks every 30 minutes kinda person?

Who knows, only you can know and the best way to be sure is to do this via experimentation during your training runs. So go out with your full kit from your ultra marathon packing list every day with your food and bag, and work out your personal refuelling strategy. 

6. Don’t Booze During Training

I like a glass of Malbec as much as… well nobody, I probably like it a lot more than the average person. However, even a couple of cheeky ones can have a deleterious effect on your running performance.

If you do drink, whatever your poison is – save it for the celebration day (which I can tell you will not be the day after running 100 miles, as you will be a total wreck). It’s wise to ban all alcohol intake during your training because this is a serious undertaking and you want to give yourself the best fighting chance for this.

Train hard, party later.

7. Hydrating Is Cool

I live in Thailand and there were days when I ran half marathons with zero drink breaks. There is nothing cool about this and I learned the hard way one day when I almost collapsed mid-run.

There are no Hardcore Harry trophies given out for idiots who are dehydrated by their own fault. Hydrate, hydrate, hydrate and top up on electrolytes during your training runs. 

I hope that you got something out of this mammoth guide on how to run 100 miles and most importantly that you also get over that finish line in one piece! Best of luck to you all and kudos to you for chasing this dream. 

Recommended reading for training for a 100 miles ultra:

Anthony Middleton

A former loser who took a risk. I now live in Chiang Mai, Thailand after visiting over 100 countries. Stay tuned for the next challenge against that clock!
Ultra runner walking in desert

Hi, I'm Anthony!

In November of 2010, I took on a mammoth challenge against the clock in a quest to upgrade my miserable life. I went out of my comfort zone and turned it all around. Ten years later, I’m completely location independent…

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