first ultramarathon

How to Step Up from Marathon to Your First Ultramarathon


By Cliff Pittman,
CTS Ultrarunning Coach

Many marathon runners are making the leap to ultramarathon distances. If you are considering your first 50k, 50-miler, 100k, or even 100-mile ultramarathon, you’re not alone. The most important thing to understand is that an ultramarathon is not simply a longer marathon. As distance and duration increase, the challenges and demands shift so significantly that ultrarunning can only be described as its own, separate running discipline. To help you successfully navigate these differences, here’s a guide to making the jump from marathon to ultramarathon training.

Road Marathons vs. Trail Ultramarathons

Road marathons and trail ultras are both footraces, but they’re as different as mountain biking is from road cycling or downhill skiing is from cross-country skiing. As an example, consider the four sub-disciplines Jason Koop identified in his book, “Training Essentials for Ultrarunning”: level running, uphill running, downhill running, and walking. Compared to trail ultras, even “hilly” road marathons are remarkably flat. It’s unlikely your marathon training plan specifically prepared you for the biomechanical differences between these aspects of ultrarunning. Here are just a few more differences between road marathons and trail ultras:

Marathon vs. Ultramarathon Pacing

As running distances increase, so do the variables that affect your pace. It’s pretty obvious that pace slows as distance increases. What’s less obvious is that ultramarathon pacing is heavily influenced by variables such elevation, ascent/descent, trail surface, significant temperature swings. As a result, you can’t always put a minutes-per-mile pace target in different sections of a race, like you would do for a road marathon.

The best approach for ultrarunning is to pace based on effort or Rate of Perceived Exertion (RPE). Running through a rock garden is slower than running on a nicely groomed gravel road, even when the effort level is the same. Regardless of the conditions, with RPE you can stay within your physiological capacities for a given duration.

Learning to pace based on RPE is an essential part of ultramarathon training. You’ll want to use data during training runs so you can learn how to race when the data may be less accurate or relevant.


In a single race, you may run on forest service roads, pavement, singletrack trails, and Jeep/ATV tracks. For instance, the JFK 50, the oldest ultra in the US, has two distinct sections. One is on the technical Appalachian Trail and the other on pavement. You might even run through water crossings, snow, or multiple microclimates depending on the change in altitude. The iconic Western States Endurance Run starts above 6,000 ft in the Sierra’s. Early on, there is often snow covering the trail. Many miles later, the course descents into canyons with triple digit heat.

Ultramarathon training must prepare you the terrain and environmental challenges specific to your goal events. This may mean learning to run with poles, a hydration vest, and extra clothing and gear. Likewise, downhill trail running and running at night are technical skills you should hone in training.

Nutrition for ultramarathons

Ultramarathons are sometimes jokingly referred to as eating contests with some running involved. That’s not far from the truth! Ultramarathon runners need to consume a moderate to high volume of food every hour for 7, 12, or up to 30 hours. And where marathon runners can focus almost entirely on carbohydrate, ultrarunners need a balance of carbohydrate, fat, and protein. Thankfully, the lower average intensity during an ultramarathon also means you can consume a variety of solid foods, drinks, and sports nutrition products. The overall nutritional approach is drastically different than a road marathon, where you rely entirely on carbohydrates, often in liquid or gel form only.

The key to mastering ultramarathon nutrition is determining which foods work for you as the hours go by. That means finding foods that will provide energy and not cause gastrointestinal distress. Just as important, you need foods you’ll actually eat after running for 12+ hours. Your tastes, cravings, and tolerance for foods change during long runs.


Hydration guidelines area also different for marathoners vs. ultrarunners. Runners who finish marathons in 3-4.5 hours can get away with some level of dehydration without terrible consequences. As the duration increases with ultras, the ramifications of dehydration increase significantly. Although hyponatremia (dangerously low blood sodium concentration) is possible during a marathon, it is more likely during an ultramarathon. And long before you reach the point of hyponatremia, there are many other ways your hydration status can get out of whack.

Part of training for ultramarathons is learning to align your fluid intake with your intensity level, nutrition strategy, and the environmental conditions (heat, humidity). There is also the challenge of carrying your own fluids. In marathons, there are typically water stations every mile. In ultras, aid stations can be hours apart.


Most ultramarathon courses are well marked, but runners it’s not uncommon for runners to take wrong turns run a few bonus miles. 50Ks can easily turn into 55Ks. And sometimes the course itself is not exactly the advertised distance. While this isn’t acceptable in road marathoning, it’s just part of ultrarunning culture.

Marathon runners may study the course to understand where the hills are, but there’s very little route finding in road marathons. As you transition to running ultramarathons, you’ll need to pay more attention to course maps. During races, you can’t turn your brain off and just follow the crowd!


In road marathons, running economy (the energy cost of running) is a very important physiological marker that can predict performance. To improve your marathon time, becoming more economical can really move the needle. In ultrarunning, we consciously sacrifice running economy for the sake of comfort, durability, and performance. Prime examples of this are the use of heavier and more durable trail shoes, running vests to carry fluids and calories, and the use of trekking poles. There are also times when you’ll purposely change your running stride length or frequency based on the terrain or pacing strategy.

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Training Tips for Transitioning from Marathons to Ultramarathons

Fitness Still Matters Most.

It’s a common misconception that ultramarathon training is just a lot of long, slow runs and hikes. Your pace during an ultramarathon may be relatively slow, compared to a marathon, but ultramarathon training incorporates the full spectrum of intensities. This is because maximizing fitness enables you to capitalize on opportunities as well as cope with adversity.

Ultramarathon training typically starts by focusing on aspects of your fitness that are least event specific. As your event approaches, your training would get more specific to the demands of the event. For example, if you have 12 months to prepare for a 100-mile ultra, you can spend the first period working on hard VO2 max interval workouts. Then you might transition to longer, more sustainable lactate threshold workouts for a few months. In the months leading up to the event, you’ll spend more time at a moderate endurance pace, but with more climbing and descending and long runs and hikes

Train by Time, Not Distance

Prescribing training volume by daily or weekly distance doesn’t make much sense for marathon, and it’s essentially useless for ultramarathons. The distance you travel doesn’t matter as much as the time you spend at specific intensity levels. For example, a 10-mile run on the track can create a very different stress than a 10-mile run in the mountains. When you consider climbs and descents, rough surfaces, and technical terrain, 10 miles in the mountains can take twice as long as 10 miles on a flat track. A mile does not always equal a mile, but an hour equals an hour. If you’re training in difficult environments or over challenging terrain, trying to hit a mileage mark that you’re used to hitting on flat roads may be a recipe for disaster.

Train Your Gut

The amount of food and fluid your gut can take in and process is trainable. As you train your gut to take in lots of calories on the move, you increase your ability to fuel long runs and reduce your risk of gastric distress. It’s important to push the limits in training to build a resilient gut. This means practicing with various foods you anticipate eating on race day. A good place to start is 200-250 Calories per hour, mostly from carbohydrates and in small portions. Carbohydrates are 4 Calories per gram, so 200-250 Calories is approximately 50-60 grams/hr. Once you’re comfortable with this, gradually increase to 300 Calories/hour and beyond.

Keep in mind, you don’t need to always consume the maximum Calories you can tolerate. When running slowly, you might only need 50 grams of carbohydrate per hour, but training your gut makes even that level of consumption less likely to cause GI distress.

What To Do Next

If you’ve read this far and still want to transition from marathons to ultramarathons, here are a few things you can do next:

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  1. Plug into your local community:

    Ultra/Trail running is growing at a rapid pace and most areas have a good community of ultra-fanatics. Inclusivity is one of the best things about our sport. So, jump into a local group run, connect with other runners, and learn from their experiences.

  2. Get a coach.

    Of course, I’m biased because I am an ultramarathon coach. There are plenty of training plans available out there, and some can even use machine learning and artificial intelligence to adjust future workouts based on recent performances. Particularly for ultramarathons, the training plan is just one component of your preparation. A coach is important for integrating the context of your life (e.g. relationships, career stress, travel, illnesses, motivations) and for teaching you how to handle the variables you’ll encounter in training and competition, like weather, nutrition challenges, gastric distress, equipment issues, etc.

  3. Start building a support network that is invested in your success.

    If you have a spouse or partner, start there! You can also consider working with a coach to help guide you through a sound approach to training. I encourage my athletes to have a physical therapist in their corner. Even if you’re not injured, a good PT can help you focus on injury prevention and make sure you’re moving well in general. Other professionals to consider for your support team include a Registered Dietitian and Sports Psychologist. These professionals are valuable assets to help you become the best version of yourself, athletically and personally.

  4. Show up!

    The single best thing you can do to have a good race day experience is show up for yourself every day of the training process. Hard work compounds over time and consistent efforts trump any single workout or long run.

My Own Marathon-to-Ultramarathon Journey

Although I’m an experienced ultramarathon runner and coach now, I once made the transition from marathon to ultramarathon. I vividly remember my thought process. Completing a few road marathons created some confidence I could prepare for and race longer distances. The transition up to a trail 50K was going to be simple. “It’s an extra 4.9 miles. I’ll just have to pace better,” I thought.

I consulted free online training plans and created my personal blueprint. I approached it just like my previous marathons: one hard interval workout, one tempo run, a long run, a second long run on the weekend, and fill in the rest of the week with easy runs. And nutrition? Well, I would do the exact same thing I did for marathons, just for an extra 4.9 miles.

Race day came and I was humbled. At the time, I was a 3-hour marathoner and this trail 50K took me almost 6.5 hours to complete. Needless to say, I wasn’t prepared. I neglected some critical components of properly training for an ultramarathon. That 6.5-hour 50K wasn’t just a longer marathon. It felt like an entirely different sport.

My hope is that, armed with the information in this article, you’ll have a much smoother transition from marathons to ultramarathons!


Comments 2

  1. Great article. Thanks for sharing. The days of running a sub 7hr trail 50k seem to be slipping away. Although I never did do a sub 3hr road marathon! I hope the newbies can take some of your wisdom to heart. Maybe these days there is too much information? Ahh where are the LISTSERVs if yester year?;-)

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