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10 Factors to Choosing Your First 50K Ultramarathon

Everything you need to know to choose an exciting and attainable first ultramarathon race

Beyond the marathon distance is the mysterious world of ultrarunning, where runners travel distances ranging from 50 kilometers to 250 miles on foot. It’s incredibly exciting to see that every year ultrarunning becomes less of a mysterious, outsider subset of running and inches closer to recognition as a sport in itself.

The danger is that as ultrarunning becomes more well known, more athletes either leap into a race without fully comprehending the demand of it, or are discouraged by the unknowns of ultrarunning. Most ultramarathoners will come from a marathon running background when they decide they want to go farther, but there are a lot of extra considerations in choosing the first ultramarathon.

It’s critical not to fall into the misconception that a 50K race is simply 8k (5 miles) longer than the traditional marathon. The overwhelming majority of 50k races are trail running events, where ground is covered at a significantly slower pace. It’s realistic to expect a first 50K to take one-and-a-half to two times longer to complete than your most recent road marathon. A 4-hour marathoner can expect a 6 - 8 hour finish time at their first 50K. A 3-hour marathoner can expect between 4.5 and 6 hours. Duration is a better way of conceptualizing how much greater the physical strain of a 50K will be.

The best chance of a successful, fun first 50K will come from training well for the specific demands of the event. More on this below.

What makes a 50K “Easy”?

Easy would typically be a flat, non-technical 50K in cool conditions at near sea level with a huge, energetic community around it. Most 50K races will present a challenge with regard to one of these points.

"The right race is attainable, but also exciting every time you think about it."

You might not choose your first 50K simply on the basis of what’s easiest. In fact, I would discourage it. The right race is attainable, but also exciting every time you think about it. There will be aspects of the race you choose that will make it a challenge unique from many of the alternative options. This article is not intended to dissuade you from pursuing a challenging goal, but is intended to be a resource so that you can make an informed race decision based on your own goals. Let’s jump in.

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Detailed Race Website

This is likely the most essential aspects to look for as an aspiring first-time 50K runner. Why?

Because good race website has a lot of information. It's an indication of professionalism that is likely to extend to the organization of the event itself, and it'll answer questions that the aspiring ultrarunner didn’t even know they had.

If the race website does not at bare minimum contain a map of the course, elevation gain/loss statistics, information about where aid stations are and what supplies they will offer, information about how the course will be marked, and at least a few pictures, STEER CLEAR.

"A good race website is an indication of professionalism that is likely to extend to the organization of the event itself, and it'll answer questions that the aspiring ultrarunner didn’t even know they had."

Likely you’ll find that races with bad websites, or worse, no website, will offer cheaper entry fees than well-marketed and clearly established races will. However, it is worth every single extra penny you will spend on the higher race fee to choose a reputable, well documented event for your first 50K. After you have a couple ultramarathons of experience, then maybe you can start to gamble on less established races that may be more of a problem-solving adventure than a physical racing challenge.

Organization and Amenities

50K course map
Frequent aid stations are perfect for the first-time ultrarunner

Some ultramarathons can be very remote, bordering on orienteering. Other ultras might have a course marking every 100 feet. In almost every situation, the first-time 50Ker will be best served at a well marked course, and these can be harder to find than in road running. By having a well marked course your mental energy is focused on less responsibilities– run, eat, hydration, cooling, etc. and not on avoiding a wrong turn that adds distance to your race.

To that same end, the kind of race that has minimal course markings is also the kind of race that’s likely to offer less amenities in the form of aid stations. Less aid stations on a course will mean carrying more supplies like food and water with you, and add importance to getting the quantity of those things right at every aid. You won’t find many mountain 50Ks with aid stations every two miles like in a road marathon, but it’s reasonable to expect an aid station every 4-7 miles in a race like that. Any less frequent than that is asking a lot from the first-time ultrarunner.

Environmental Conditions and Times of Year

Races can occur in a lot of different environmental conditions. Excluding but not completely ignoring the freak scenarios where runners are caught in a hail storm, races can be in hot or cold weather, dry and sunny or humid and rainy, at sea level or at high altitude, windy or still. That's a lot of different conditions you could find yourself in.

Coastal or high alpine races will often times experience significant winds. In many places winter is windier than summer. Some athletes are more well suited for cooler conditions whereas others can still perform very well in hot conditions compared to their competitors. Think about the experience you’d most like to have. That might mean you are comfortable and run well in cool, wet conditions so you choose a race that’s likely to experience cool and wet conditions. It might also mean the same athlete is looking to challenge themselves to perform well in heat, so they choose a race likely to face that weather instead.

Typically environmental conditions will be just a checkbox, rather than the primary goal aspect we select for. Most of us are not inspired to run 50K by particular conditions, but by the other aspects of the experience discussed here.

Training Convenience

Where do you normally train, or what’s logistically possible to access? If you live somewhere flat like the Great Plains in the United States, you will probably not want to sign up for an exceptionally mountainous race because you won’t be able to train for it by climbing and descending mountains. Likewise, if you have mountainous trails out your back door that you love training on, a race on flat or even paved surfaces could feel outside of your wheelhouse when race day comes.

Preferred Training Style

One of the most important aspects in choosing your first 50K should be asking yourself what you like to do in training. You will spend weeks and/or hopefully months training for your first 50K, but only a single day racing it. Running is supposed to be fun, not a burden, so set yourself up to be motivated by training the way you like to train rather than forcing yourself to train in a way you don’t like or is very new. If you like running up and down mountains on the weekend in Colorado, then a mountainous, high altitude race is probably the kind you want to sign up for because it will enable you to spend your leisure hours doing something you enjoy. If you prefer to run a high volume of fast and flat road miles, then you’d be better off signing up for a race that requires the sort of fitness you will develop by training that way.


Most races of the 50K distance will be governed by certain course cutoffs, meaning if a runner is not through Point X of the race by Time Y, they will not be allowed to continue the course, receiving a DNF (Did Not Finish). There is a huge amount of variation in the cutoffs of different races. Some race courses may not look particularly challenging but will have cutoffs that require runners to be moving surprisingly fast. Other races may have cutoffs only as a formality, being lenient enough that they pose little threat to ending a runner's race early. Cutoffs for any course will be determined (and should be clearly posted on the race website) by permitting from local authorities, the terrain of the course, the demands on aid station volunteers, and the race organizer's preferences, among other things.

Understanding how much of a barrier cutoffs will pose to you requires an analytical eye. You'll want to consider the pace required to make all course cutoffs as well as how difficult the terrain between cutoff points will be, and then check that against your understanding of your own fitness and training paces. This is often challenging for the first-time ultrarunner with limited experience to draw on, and in many cases your best bet will be to research what others have said about the event online (which will be quite a lot since you'll be choosing a well established event for your first race). If past participants are noting cutoffs as being close or bringing their day to an early end, you might not want to risk it.

"Some race courses may not look particularly challenging but will have cutoffs that require runners to be moving surprisingly fast.
Other races may have cutoffs only as a formality, being lenient enough that they pose little threat to ending a runner's race early. "


Some athletes want to start with what they know, signing up for a 50K in their backyard. It can be a smart decision that sets you up for success, even allowing these athletes to train on the race course in the buildup to race day. Some athletes prefer a destination race that takes them to one of their favorite far-from-home places or takes them to an entirely new place. Geographical location will influence the environmental conditions you face on race day. It will be best to either choose a race and train for those conditions, or to choose a race which matches the conditions you’ll most conveniently be able to train for. Just as with shorter distance races, traveling to a race destination introduces some logistical challenges and can be a stressor days to hours before race start.


Often times thousands to tens of thousands of spectators will be found at major road marathons. These races occur in cities where many people live and can easily come out to spectate and provide some stoke for tired runners in those late miles.

Ultrarunning's not always like that. There are many races where the field of runners will be only a couple of hundred competitors, and there will often be even fewer spectators providing support, spread out across the 31 mile race course. The community and energy around a race significantly influences the experience you have. Many runners will do best at a high-energy event with lots of people around to cheer them on, and some racers will look for a course that provides solitude out in nature instead of boisterous fans.

Lotteries and Waitlists

Lotteries are far more common in the world of ultrarunning than in road running events. Ultra distances require more staff spread over a greater area, oftentimes in hard-to-access places. In addition, land permitting for protected nature areas that a race runs through are a significant factor to trail ultras that’s rarely encountered by road races of marathon distance or less. These added constraints mean only a few hundred entrants may be allowed to participate; a stark contrast from events like the Chicago Marathon. You’ll find that the top 10 most renowned 50K races will be under lottery because their reputation generates runner interest well beyond what the race is able to manage.

Western States WSER start
Western States Endurance Run has one of the most competitive race lotteries in the world with only about 5% acceptance rate each year, and waitlisted individuals being invited to participate only hours before the 100 Mile race start

After this top 10 is the best place to look for that first race. These are the races that don’t have a lottery so you can definitely sign up, but they are also well established with a clear website and hopefully many successful runnings already in the rearview.

Why avoid the lottery for the first race longer than a marathon? These add additional degrees of uncertainty way beyond what most entrants are expecting. With lotteries themselves, you typically know months before the races if you’ll be allowed to participate but many lotteries also draw for a waitlist, which is often a loose cannon. Names from the waitlist are called to participate if an already-registered entrant withdraws before the race starts. Waitlist names start getting called more rapidly as a race approaches and athletes realize they won't be able to participate, so runners on the race waitlist are regularly extended an invitation from a few weeks before, to even a few hours before the starting gun goes off.

Most of us need a focused and predictable training cycle to succeed at that first 50K, and the nature of lotteries and waitlists is unpredictable and best avoided until we're more fit for the distance.

"Runners on the race waitlist are regularly extended an invitation from a few weeks before, to even a few hours before the starting gun goes off. "

Nervous Excitement

As one of the most advanced 50K races in the world, The Rut Mountain Runs is sure to instill nervous excitement in all its participants

There is one qualifier that I believe is absolutely essential for every runner as they choose to take on their first 50K run: emotion. Running is, for most of us, a hobby. Recreation is supposed to be enjoyable, and you should be excited about the race you are choosing to run and train for! Every other item on this list is a strategic decision founded in logic that will enhance your chances of success, but no amount of logic is going to will you to the finish line when the going gets tough in the late miles of your race, or even on the intimidating training days as you prepare for your race. Whatever race you choose should inspire excitement, albeit with the proper respect for the race’s challenges.

Search Resources

Running, especially ultrarunning, still lacks a reliable one-stop-shop race searching. Ultramarathon websites are spread out across the web and may not appear in anything but the most verbatim Google searches. If you're looking for a database of race dates, lengths, and locations like at, here are some of the first places to begin the search for your first 50K.



The most popular platform for race registrations is Many race organizers choose to use Ultrasignup to streamline their race registration flows, and the benefit to prospective runners is that the registration pages for races on Ultrasignup typically offer a lot of important details about the event right up front, and with a link out to the event's primary website for the rest of the details. UltraSignup is far from comprehensive, however, and their search-and-filter tools are not especially user friendly. Still, it is likely the best place to start looking for an event because it offers the most robust database of races available.


Ultrarunning Magazine's website offers a superior user interface, with options to search from a map, a calendar, or by state. The races on this page are likely to be well established and thus good candidates for the first 50K. The drawback is that only a small number of races are available from this page.



This database, which includes events across a wide range or sport types, is also fairly robust. It offers simple but effective search-and-filter tools. Event listings on ahotu are sparse, conveying little more than the race distance, date, and location. Users will need to follow through the website link to learn anything more about the event.

Conclusion and Suggested Races

Running is a sport about pushing our limits physically and mentally. Still, making the transition to ultramarathon races can be an intimidating jump.

Success is possible. With a little thought to these factors, you can confidently choose a first ultramarathon that you're excited to train for and ready to put your best foot forward at on race day.

Below are a few of our picks for an athlete's first 50K:

Wyeast trailfest logo

Wy'East Wonder by GoBeyond Racing. Flowy single track trail racing in an incredibly scenic area near Mount Hood in Oregon.

javelina jangover logo

The Javelina Jangover by Aravaipa Running. A fast and fun overnight race on rolling desert single track with fast smooth sections and challenging mountainous sections.


Dead Horse by Mad Moose Event. World class single track trail in Moab, Utah with stunning views of Arches National Park, the La Sal Mountains, and Moab Valley.

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