What Is an Ultramarathon?

Rear view of fitness woman runner running on road

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Running is a sport you can perform almost everywhere, right out your front door, on your lunch break, and when traveling. You do not need expensive monthly gym fees or equipment, and you do not need to pack much to keep up with your running workouts while on vacation. It's an accessible sport with many levels—it's up to you to decide which level you strive for.

Every year, many runners choose to train for a running race. In 2019, 17.6 million people registered for running races—5K was the most popular distance. Runners with more extreme fitness goals register for an ultramarathon.

What Is an Ultramarathon?

An ultramarathon is any race that is longer than a traditional marathon distance of 26.2 miles. The number of races and number of finishers has grown exponentially in the last 30 years and can be categorized in different ways.

  • Distance-based ultramarathon: These races ask runners to complete a defined distance. Some of the most popular distances for ultramarathon races include 50K, 50 miles, 100K, and 100 miles.
  • Time-based ultramarathon: These races are confined by a certain number of hours, rather than distance. There are generally three different time frames used for these races—6 hours, 12 hours, and 24 hours. Most timed ultras involve a loop course from a few miles to several miles long. Participants have the option to stop at the end of the loop for fueling or rest as needed, and can then jump back into the race.
  • Obstacle racing ultramarathon: Similar to the races above, participants either tackle a long-course event or complete a multi-lap timed event. A popular example of an obstacle race is the Tough Mudder—obstacle ultramarathons add time or distance to this already difficult race.

Ultramarathons take place throughout the world, often in remote locations, at high elevations, and on trails away from traffic; closing roads for long periods of time is expensive and challenging for race directors. Popular ultramarathons take place in Nevada, New York, South Africa, Greece, and Morocco.

Pros and Cons of Ultramarathon Training

Clearly, training for a long-course endurance race means you’ll spend a lot of time exercising. With that comes several pros and cons to be aware of.

  • Regular cardio may reduce risk of disease

  • Mental health boost from positive endorphins

  • Sense of pride

  • Excessive exercise could lead to cardiac concerns

  • If not paired with strength training, loss of muscle mass

  • Possible injury due to overuse

How to Train for an Ultramarathon

Training for an ultramarathon requires time management, commitment, and following an intense training plan with hours of running. To follow an ultramarathon workout routine, you need several months to train. Research-based tips for creating a running schedule are as follows:

If you're new to ultramarathons, an endurance coach can be a valuable resource for creating a training plan that takes your current fitness level into consideration while progressing workouts toward your goal.

Build a Base of Long Runs

Every runner starts from a different place. That being said, if you're training for an ultramarathon, a foundation of distance running will be helpful as you begin to progress in mileage. Completing a traditional marathon before you start training for an ultramarathon will give you a solid base to build upon.

Schedule Your Training Runs

Once you develop your base and want to move up in mileage, you can develop your schedule. These high-running weeks usually occur at weeks 16 to 20 of training. This includes one week of high mileage, including long runs on both Saturday and Sunday (or whatever back-to-back days work for your schedule), and then a recovery week.

Get in Your Highest Mileage Week

This should occur about three weeks to a month before the race. All your runs up to this point should increase in volume and intensity, and you might want to consider running twice per day to build up endurance. In the training plan for the Umstead 100, a 100-mile race in North Carolina, race directors recommend a minimum weekly mileage of 60 to 70 miles, and up to 90 if you can.

Decide Your Taper Strategy

After your highest mileage week, you begin to taper. You can now decrease the length and pace of your runs. This allows runners to reduce the stress of the high mileage they put on their body over the past number of weeks. In a recent study, researchers found that three weeks of tapering led to a superior finish time.

There are two key differences to consider when training for an ultramarathon compared to a standard marathon road race:

  • Terrain: Since most ultramarathons are run on trails, it’s wise to structure your training plan with a lot of trail running experience.
  • Pacing: While many runners have an idea of a comfortable pace on a flat road, trails are a different experience. Trails vary in their difficulty and elevation. A mile that normally takes you 10 minutes on the road may take several extra minutes on the trail. Because of this, many ultramarathon training plans may include a combination of time-based runs and distance-based runs in order to keep you training well without frustration over pace.

Nutrition Tips for Ultramarathoners

To maintain the energy you need to complete the long runs, optimal nutrition is necessary. If you have any questions about what should be included in your nutrition plan, or how to get enough calories for the high-intensity training you're doing, speak to a registered dietitian.

Foods to Add to Your Diet

For an ultramarathon, you should consider calories, as well as your choice of carbohydrates, lipids, and lean proteins. Below are some nutritious options to add to your diet:

  • Sweet potatoes
  • Brown rice
  • Quinoa
  • Olive oil
  • Avocados
  • Leafy greens
  • Salmon

How to Get Enough Calories for Ultramarathon Training

During a race, carbohydrates are generally the most important source of energy. For caloric deficits while running, runners should consume 150 to 400 calories per hour (with 88 percent of the caloric choices being carbs) and 450 to 750 milliliters per hour for hydration.

Staying Hydrated

To mitigate your chances of hyponatremia (when the sodium in your body is substantially low), your hydration should include electrolytes. Runners who can tolerate caffeine can use it in their food and fluid intake to sustain performance in the latter stages of the race.

Avoid overdrinking on long training runs. Drinking too much water while running can increase your risk of a dangerous condition called hyponatremia, or a dilution in blood sodium levels. Most athletes can self-regulate by drinking according to thirst.

Safety Tips for Ultramarathon Training

Safety should be your number one priority throughout your training and during your race. The Road
Runner Clubs of America provides tips to lessen your risk of danger:

  • Stay alert: Be aware of your surroundings.
  • Remove headphones: You might want to run without music to stay more cognizant of what is going on around you.
  • Change your running route: Do not post your route online as you run.
  • Stay visible in the dark: Invest in some reflective clothing and stay in lit areas if you can.
  • Join a group: Running with people provides safety in numbers.

Recommended Ultramarathon Races in the U.S.

If you’re thinking about completing an ultramarathon, these are some of the most notable races throughout the United States:

  • Western States Endurance Run: This is the world’s oldest 100-mile trail race, taking place in June each year in California. Not for the faint of heart, runners are subjected to 18,000 feet of climbing and 23,000 feet of descending to reach the finish line. It’s a legendary event that any experienced ultramarathoner would love to experience—but keep in mind, it’s a lottery-based entry system.
  • Anchor Down Ultra: Known as “the smallest state’s longest race,” the Anchor Down Ultra is a time-based ultramarathon event in Bristol, RI. It includes a 6-hour, 12-hour, 24-hour, and 100-mile race (the latter is built into the 24-hour race). Runners loop around a 2.45-mile course, passing beautiful waterfront scenery during this challenging (but beginner-friendly) August event.
  • Chuckanut 50K: This mountain ultra includes 5,000 feet of climbing among the Chuckanut Mountain Ridge in the beautiful Pacific Northwest. Not only does this March race come highly recommended, but the race also encourages participants to give back to their communities. Part of the entry requirement is to complete at least 4 hours of service work (trail work or volunteering at a race) or to make a donation to a trail organization.
  • Wild Woman 50K: While men still outnumber women in the ultrarunning scene, that gap is starting to close a bit. This race is proof—it’s a trail marathon, relay, and 50K, specifically for women. The event takes place in June in Washington state, around the base of Mt. Adams.
  • JFK 50 Mile: This is another historic race, with the first event dating back to 1963. While the first 15 miles of the race is focused on some challenging trail running, the remainder of the race is focused on flat or lightly rolling dirt/gravel trails or paved roads.
  • Self-Transcendence 3100 Mile Race: If you are already an experienced ultramarathoner and want to give yourself the ultimate challenge, this is the race to choose. It’s the world’s longest certified road race, lasting from 6 am to midnight for 52 days straight from June through August. Athletes try to hit 3,100 miles during this time frame, which averages out to almost 60 miles each day, by looping around a half-mile block in Queens, NY.

A Word From Verywell

Runners who choose a fitness endeavor like an ultramarathon will need to train for several months and follow a nutrition plan with nutritious carbs, lipids, and proteins. If you are immunocompromised, have any concerns, or just want to be sure an ultramarathon is a safe goal for you to have, speak with a medical professional before beginning any running program.  

Frequently Asked Questions

  • What should you eat before an ultramarathon?

    A couple of days before a marathon, you should consider following specific meals plans with a macronutrient distribution of 60 percent carbohydrates, 15 percent protein, and 25 percent fat. Faster or individuals with higher weight might want to increase their fat intake. Overall, nutrition before an ultramarathon should be individualized based on training, resting heart rate, activity level, body composition, and environmental conditions.

  • What do you wear for an ultramarathon?

    For an ultramarathon, you want to dress appropriately, keeping comfort and anti-chafing top of mind. You can experiment as you train to discover what works best for you. Items you might want to consider include the following: running shorts, a sweat-wicking T-shirt to keep you dry, running shoes, a hydration vest, and a waist pack for nutrition and hydration.

  • How do you qualify for an ultramarathon?

    Most ultramarathons do not require runners to formally qualify. These races are open to any runner, but you need to train to finish them. The smallest distance is 50K, which is about 31 miles. Some require a high base of running already before you want to even consider registering. The distances of certain extreme ultramarathons can range from 150 miles (Marathon Des Sables in the Sahara Desert, Africa) to 3,100 miles (Self-Transcendence 3100 in New York).

8 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Running USA. 2020 Running Trends.

  2. Knechtle B, Nikolaidis PT. Physiology and pathophysiology in ultra-marathon runningFront Physiol. 2018;9:634. doi:10.3389/fphys.2018.00634

  3. Nikolaidis PT, Knechtle C, Ramirez-Campillo R, Vancini RL, Rosemann T, Knechtle B. Training and body composition during preparation for a 48-hour ultra-marathon race: a case study of a master athleteInternational Journal of Environmental Research and Public Health. 2019;16(6):903. doi:10.3390/ijerph16060903

  4. Umstead 100. How to Train For and Run Your First 100 at the Umstead 100.

  5. Smyth B, Lawlor A. Longer disciplined tapers improve marathon performance for recreational runnersFront Sports Act Living. 2021;0. doi:10.3389/fspor.2021.735220/full

  6. Tiller NB, Roberts JD, Beasley L, et al. International Society of Sports Nutrition Position Stand: nutritional considerations for single-stage ultra-marathon training and racingJournal of the International Society of Sports Nutrition. 2019;16(1):50. doi:10.1186/s12970-019-0312-9

  7. Road Runner Clubs of America. Runner Safety Tips.

  8. Martínez-Navarro I, Sanchez-Gómez JM, Aparicio I, et al. Effect of mountain ultramarathon distance competition on biochemical variables, respiratory and lower-limb fatiguePLOS ONE. 2020;15(9):e0238846. doi:10.1371/journal.pone.0238846

Additional Reading

By Jennifer Purdie, M.Ed, CPT
Jennifer Purdie, M.Ed, is a certified personal trainer, freelance writer, and author of "Growth Mindset for Athletes, Coaches and Trainers."