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100 Mile Run Training Plan (FREE Printable)

100 Mile Run Training Plan (FREE Printable)

Welcome to the pinnacle of ultra running: the 100 miler. A lot of people can run a 50k and claim the title of ultra runner, but what do they say to the inevitable follow up question, “Have you run a 100?” Let’s make sure your answer to that question is a resounding YES!

There’s nothing easy about finishing a 100. Sure, some courses are harder than others, but no 100 is easy. No matter what, if you finish the race, you deserve to scream that accomplishment from the mountain tops for the rest of your days. There is absolutely nothing like crossing that finish line. No matter how you slice it, during the course of the race, you will experience the full range of human emotion. 

Personally, I’ve finished about 40 trail ultras, and a ton of road marathons, half marathons, 10ks, and 5ks. I don’t save any of the finisher medals, ribbons, or other commemorative items you get at most of these races. I never buy the shirt. But you better believe I have my four 100 mile belt buckles mounted on my bedroom wall!

They each rest on the ledge of a wooden frame that holds an image that encapsulates the event: the race logo, the map, the course profile, and a few pictures from the race. I will never forget my 100s. And if we ever meet and you ask me about them, I will gush like a schoolgirl and tell you the play by play until things get real weird. 

I’m excited that you’re seeking out a training plan! Especially if you’re going to be attempting your first 100. I’m going to do my best here to set you up for success. Let’s get you that finishers belt buckle!

Rio del Lago (2014), UTMB (2015), Run Rabbit Run (2016), The Bear (2018)

How do I prepare for a 100 mile run?

There are many paths to the top of the mountain as they say, but I’m going to provide you with a well beaten, tried and true path, that if followed closely will get you to that finish line. It’s important that we have a long slow buildup to the run. The plan I provide below is 24 weeks long!

The reason for that is to make sure your body had adequate time to acclimatize to the workload. I want to bring you along slowly so that you can stay healthy, mentally and emotionally strong, and feeling fresh on the day of the event. 


The key to building ultra fitness is similar to building any sort of aerobic fitness: you stress your body, you break it down and beat it up, and then you give it time to heal and strengthen and ultimately improve.

As you’ll see, I like to prescribe two consecutive weeks of increasing workload, followed by one week of rest and recovery where your volume and intensity will decrease 30-40%. For example, we’ll build weekly mileage like this: 20, 25, 15, 25, 30, 20, 30, 35, 25. Nice and slow. 

Types of training runs

You’d think that all you need to do is go out and run a bunch of slow miles because that’s pretty much what you’ll be doing on race day: the 100 mile shuffle. We will do some of that, especially on your weekend long run days, but I also think it’s important to get as physically fit as you can.

In order to do that, about 12 weeks into your training plan, we’ll implement other training strategies like tempo runs and interval training. More on those below.  


Next, I’ll lay out a plan that allows you to customize with specificity to meet the unique challenges of the course and environment of your race. Example: If you live in Nebraska and you’re racing Western States, you need to prepare for the heat and the quad-destroying downfalls of that course in order to set you up for success.

If you’re from Oregon and you’re running H.U.R.T. 100 in Hawaii, you need to up your technical running skills and prepare for the humidity. I’ll provide the framework but it’s up to you to flesh it out to meet your specific needs.

Gear and Nutrition

Lastly, gear and nutrition play a HUGE role in 100 milers. We aren’t going to do a deep dive on those topics because they really need an entire article to themselves. But suffice it to say, your gear and nutrition strategy is just as important as your training strategy so make sure you have them dialed in.

The last thing you want to be worrying about on race day is whether or not your headlamp batteries are going to last through the night or if your stomach is going to like a food from the aid stations. You want to be so prepared with your gear and nutrition that you can turn that part of your brain off and focus on the physical workload alone without any unneeded stressors or hindrances. 

24 Week 100 Mile Ultra Marathon Training Plan (Printable)

(Printing instructions – click the image above to open the .pdf printable in a new window. When you print, select “fit to page”)

The training plan explained

For those of you who are unfamiliar with a lot of the terminology included in the training plan, don’t worry, I’ll go through each instruction and let you know exactly what it’ll mean for you. 


This is pretty self-explanatory. The idea is to take an entire day to recovery and let your body repair itself. No cross-training, no cardio, no strength. This doesn’t mean you can’t go on a walk around your neighborhood or a take a short hike with your family or hop on the cruiser bike to go pick up your coffee and croissant, just don’t cross that line into any sort of aerobic effort. 


Cross-training is extremely important. As runners, we don’t want to be a “one trick pony.” If you only ever stress the muscles you use for running, you aren’t going to develop any of the other stabilizer and supportive muscles that will keep you healthy over the long haul. So what is cross-training? Really, it’s anything that gets your sweat flowing and your blood pumping.

I recommend finding something that’s fun and easy to get yourself to do. The last thing you need is a sense of dread that you have to force yourself to do. Find something you actually enjoy! Some examples to consider: yoga, mountain biking, bouldering, punching bag, swimming, or intense paddle-boarding. Shoot for 30-90 minutes depending on the intensity of the activity. 

Strength Training

Strength training is another wonderful tool, especially to help runners remain injury free. Similar to cross-training, strength-training helps build and strengthen your supportive muscles and joints so that you don’t suffer from an overuse running injury that are so common for runners. If you google 30 minute strength workout, you will be slammed by a million options to consider.

I am someone who likes to do my strength work at home. I also hate using free weights so I rely on a body weight routine designed for runners. Here’s a link to a program I have used for years: the Oregon Project Stability Routine

If, alternatively, you like the gym environment and using free weights, go for it! Find a program that works for you and that you can fit into your daily routine.

Also read: What Strength Training Should Runners Do?

Tempo Run

Tempo runs are a type of speed workout where you run at a sustained effort, faster than your normal easy run pace. You push yourself to a place of elevated breathing but not so hard that you go over your own personal redline. The goal is to aim for 70-80% of maximum effort where you are stressing your cardiovascular system but not building up lactic acid in your muscles as you would in a race.

This is your lactate threshold pace as shown in the training plan. 


Intervals are short bursts of intense running where you flip-flop between fast running and recovery. Five intervals of three minutes hard running followed by three minutes of jogging/walking is a prime example. The goal here is to get up to a pace of 80-90% of maximum effort during the hard intervals.

You shouldn’t be able to manage a conversation with a running partner due to labored breathing. Make sure to not start out too hard on these though! You want to cover roughly the same distance during your last interval as you do on your first. 

A note about weekly running volume and weekend long runs…

You’ll find that the training plan actually starts out pretty easy! But don’t be fooled, the volume will sneak up on you until eventually you feel like you’re drowning in it. And that’s how it’s supposed to feel. It’s a slow build up so that both your body and mind have a chance to adapt to the training.

As I mentioned, I prescribe a two-week build, followed by a rest week with less volume. To start, I include strength and cross-training days but those will slowly get replaced by more and more running miles. Your weekend runs will also progress until you hit the peak of covering almost 50 miles in one weekend! That might seem crazy at this point in time, but trust me, when the time comes, you’ll be ready for it! 

The “back-to-back long run” is one of the staples of ultra running training. A long run on Saturday followed by a long run on Sunday. The way your legs will feel on Sunday is about as close as you can get to simulating what it’ll feel like in the latter stages of a 100 miler.


Also read:

What to put in Ultramarathon Drop Bags? (50k to 100+ Miler Essentials)

How Long Does A 100 Mile Run Take?

How Long Does it Take to Run 200 Miles? Trail Running FAQs


Simulate your race course (elevation gain and terrain)

One of the difficult parts of creating a one-size-fits-all training plan is that I obviously can’t customize the training to each individual’s goals and needs. For example, if I were coaching an individual to prepare for Run Rabbit Run 100, which starts at 6,700 feet of elevation and has over 20,000 feet of vertical gain, I would want the runner to be training with specificity in mind.

First off, if you aren’t accustomed to high elevation, you might want to plan a few weekend trips to get up to high altitude so you can experience the thin air. And with that kind of vertical gain, you are going to want to integrate uphills into almost every run you do! Contrast that with the runner who is taking on Rocky Raccoon 100 in Texas, a course with only 5,000 feet of rolling terrain.

In that case, your daily easy runs would include little to no steep uphills. You’d want to become very comfortable running for long stretches at a time with no breaks. Rocky Racoon is also a loop course where you run four 25 mile loops. I’d recommend you practice running loops on your long runs so that you can mentally prepare for that experience. 

So because I can’t tailor the plan to every race, I recommend you take a look at the elevation profile, the altitude of the course, the types of terrain you’ll find, and any other unique qualities you’ll face on race day. Make a list and then implement them into your training as much as possible.

Feel free to adjust your mileage slightly to take into account the time it will take you to run a lot of uphills. If the plan says to run 6 miles and the race you are preparing for has a ton of vertical gain, drop your mileage down to 4 or 5 to account for the 1,000 feet of elevation gain you’ll cover during the run.

How to modify the training plan for shorter and longer time-frames:

I created a 24 week plan because I felt that was the minimum amount of time needed for someone with a basic level of fitness. If, however, you are fairly fit already, you might not need all 24 weeks. Maybe you’re coming off a 50k race or a road marathon and you don’t need to lay much of a foundation in preparation for your 100 miler.

In that case, you could get away with eliminating the first 4-8 weeks of the training plan. Anything less than 16 weeks of dedicated training, however, makes me a littler nervous for you. 

Alternatively, if you feel like you’d like a little extra time in your dedicated build up, by all means, start your training early! For you, I’d recommend taking the first 4-8 weeks of the training plan and do it twice in a row. This could be especially beneficial if you haven’t been doing any cross-training or strength training so you can start to build up your muscular support structure. 

Minimum training for 100 mile race?

The minimum training required to complete a 100 mile race really depends on the cutoff times of the specific race in question. If you aren’t familiar with cutoffs, they are time and pace benchmarks that need to be met along the way for the race organization to allow you to continue on.

Every race will post their time cutoffs so you know how fast you need to be moving to have a chance at finishing. For example, the race might require you reach X aid station by 6pm. All runners who arrive later than 6pm will be shuttled back to the start/finish line and given the notorious DNF (did not finish).

My understanding is that these cutoffs exist so that volunteers don’t have to be out on the course forever waiting for just a couple runners. There are also liability concerns for those who are really struggling. 

Now, some cutoffs are more lenient than others. If your goal is to train minimally, then I’d recommend finding a 100 miler with very generous cutoff times. If you have 48 hours to finish the race, then you know you must complete 50 miles per day. Plan and train with those paces in mind.

One other quirky consideration is the hard 100k test. I made that name up. I believe that if you sign up for a hard mountainous 100k and finish that race, then you are likely prepared to run a flatter easier 100 mile. 

How do elite level 100 mile training plans differ from mid-packers?

A training plan for an elite differs greatly from your average mid-packer’s who simply wants to finish as quickly as they can. First of all, the weekly volume is typically much higher. Imagine 2x the training plan I wrote above. There would also be more speed workout sessions to really develop the cardio engine.

Even in 100 mile racing, an elite is running fairly quickly from the start. They can’t afford to simply settle into a slow easy comfortable pace for the first 50 miles. They must be so fit that their casual pace is actual pretty fast. 


Elites also tend to place a lot of emphasis on tune-up races. They’ll typically run a few shorter ultras en route to the 100 miler so that they can really dial in their fitness, nutrition, gear, and tactics. These shorter races are incredible workouts and fitness builders that are hard to simulate in training. 

Some elites also utilize advanced training metrics like heart rate. They might have preset heart rate zones that they use to both keep them from training too hard and to make sure they’re training hard enough. Their coaches can then monitor them more closely and further customize the training regimen.

Lastly, an elite likely has a very strict strength and conditioning program to keep them from getting injured and to improve performance. To be an elite, you really have to adopt a holistic lifestyle. You’re either running, fueling, or recovering with great care at all times. 

Can I go from the couch to a 100 mile run?

As a dreamer myself, I definitely understand the shoot for the stars mentality. So you aren’t interested in working your way up the ladder from 50k to 50 miler to 100k to 100 miler. You’re fixated on the 100 mile distance and that’s the race that’s going to get you out the door to train. I get it and I honestly think it can be done. 

That said, you’re going to have to be strategic. Find an easier course with lenient cutoff times. Next, start training now! No joke, after you finish reading this, lace up your shoes and get your first run in. It’s important to not wait a day longer. You need to get the ball rolling and start building fitness.

To set yourself up for success, I would not register for a race that is any sooner than six months from now. If you’re truly starting from scratch, injury prevention is likely going to be your biggest hurdle, so the more time you have to ease into the training, the better. 

If you accomplish the couch to 100, you’ll be in rare company. In looking back at my ultra results, I ran 10 ultras before I ran my first 100 miler. But I did skip the 100k distance! Just lots of 50ks and 50 milers. 

I’d recommend taking the first 12 weeks of the training plan above and do it twice so that you have a full 36 weeks to prepare. And then, if you work the program diligently and make it to the starting line healthy, then I’d say you’ve set yourself up to finish! 

What about running 100 miles WITHOUT training?

Okay, okay, I feel like I’ve been very optimistic in this article. I don’t want to crush anyone’s dreams, but trying to run 100 miles without training is not possible. I can assure you that there will be very little running happening on race day if you don’t train. You might get through 10 or maybe even 20 miles of running, but after that you will most likely be reduced to a painfully slow walk that will progressively deteriorate into a limp and a stagger.

Then, you’ll enter an aid station and either fail to meet the cutoff or simply succumb to the pain and discomfort of it all and call it quits. This is sort of like trying to go pass the bar exam without going to law school. Or a massage therapist attempting open heart surgery. It’s ludicrous and not advised.

The only potential scenario I can see this working is if you just got done with a long backpacking trip or thru-hike and you’re able to roll that walking fitness into the 100 miler. Can you finish 100 miler without any running training? Well, yes, if you’re a very strong hiker. There are 100 milers out there where you only have to cover 2-3 miles per hour to beat the cutoffs.

So, hypothetically, you could walk the entire race. What you’ll need to do, however, is spend very little time in the aid stations, stay properly hydrated and fueled, put your head down, and walk quickly for 36-48 hours straight.  You’ll need to find the right course and terrain to pull it off. But if you set out to try to run the whole thing without any run training, get ready for a cruel type of torture. 

Time to get to work!

I hope you enjoyed this article and are excited to get to work on the training plan. I’d love to know if you end up using it! The key to 100 mile training is simply not giving up. It’s hard, it’s time intensive, it’ll hurt, but if you manage to get yourself to that finish line, there’s truly nothing sweeter. The memory will hold up over time and it’ll be something you’re proud of for the rest of your life.

Be brave. Take the leap. Work hard and you’ll get it done. I’m rooting for you! Best of luck in your training and running 100 miles!


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Matty D!

Friday 16th of April 2021

Chase! Dang I've read a LOT of books, articles, even haikus on ultra-running. I've only finished 3 50mile ultras, but can attest to the rigors of training/racing and the incomparable joy of the accomplishment. I mean, c'mon, is there really ANY better feeling than crossing that finish line and hugging your crew?! (Ok yeah, I don't have kids) Anyway, you've nailed it on this piece, well done. I'm currently training for my first 100, the iconic LT100, and could not be more excited. I'm somewhere between elite and mid-pack, but damn I want to achieve my potential in August. Thanks for the sage words, training outline, and REALness in your character. With a lot of hard work and a little luck I'll be framing my first buckle on the wall this fall! (After I wear it 24/7 for a few months, 😂😂 Cheers to all your accomplishments and happy running!