How Long is a 50K in Miles? Complete Guide to 50K Training (2024)

If you’ve run a few marathons, you might have started eyeing an ultramarathon.

The first distance that comes up after a marathon is a 50K.

50K is not a 50-mile race, but actually a 50-kilometer race which equals about 31.07 miles. That’s 5 miles more than a standard marathon.

It might seem daunting to train for an ultramarathon, but it doesn’t have to be. There are certain things to keep in mind but it’s definitely a realistic goal if you’ve run a marathon already. You’ll soon realize that ultrarunning is a different beast than marathon training.

Especially when tackling your first because there is no pressure of chasing a PR! Your first time completing the distance makes it an automatic PR.

All the more reason to enjoy the ride, so you’ve got something to beat when you do it again…because there’s always another, right?!

The biggest difference will be if you are doing a road or trail 50K because the time on feet increases with the amount of vert or technical trail.

In this article, we’ll discuss not only what a 50K is in miles, but also how to choose your first 50K race, which beginner-friendly races you should look into, the gear you’ll need, and how to train for a 50K.

What is a 50K?

A 50K is the first distance that we recognize as an ultramarathon, though technically anything over 26.2 enters that territory. It can also be known as ultra-distance.

The majority of 50K races are on trails because it’s easier on the body and trail runners just enjoy being out there longer and upping the challenge.

Every race is so different, and unlike road racing, it becomes harder to compare yourself to others or even with yourself! One race might have 2,000 feet of vertical climbing and another 10,000 feet with scrambling.

Training for yourfirst 50Krequires a similar effort as marathon training, but usually with less speed work and more back-to-back long run days.

Just like marathon training, you won’t be running close to the full distance in one shot and don’t need to.

How Long is a 50K in Miles?

50K in miles equals exactly 31.07 milesif we’re being super technical, but 31 miles is the average accepted distance.

What you may notice with trail races is they aren’t as exact as road races. So it’s very possible for a 50K to be 32 miles, this is increasingly true as the distance of the race gets longer and longer.

This is why it’s recommended that runners planning to run a 50K should have completed more than one marathon at the very least so that they’re confident those additional miles won’t be too much of a significant challenge.

For this reason, ultramarathons are usually better suited for intermediate runners or more advanced runners looking for a new challenge.

How Long Does It Take to Run a 50K?

This is a tricky question to answer because it depends a great deal on the course. How much vertical is there? How technical is it? Do you need to navigate or is the path easy to follow?

There’s also an assumption that there will be some walking in your race. Trail runners call this power hiking to conserve energy!

For this reason, you’ll usually run your 50K slower than your standard marathon pace. This means you could need anywhere from6 hours for a very speed runner to 10 hours with a lot of walking.

Beginner 50K Training Plan

If you can run a marathon, then you can run a 50K.

At just five miles longer than the marathon distance, you don’t have to tack on much more volume than you would a typical marathon training plan.

Training plans for a 50K run about 24 weeks, if you’re a beginner or average 20-30 miles per week, giving you time to build up that weekly mileage.

You don’t want your total for the week to be less than the full race distance :).

I’ve seen low mileage 50K training plan and they tend to assume that you are doing some other more intense workouts like CrossFit, HIIT running workouts or speed on the bike with your Peloton.

If you’ve recently run a half marathon or marathon, you can jump into the training plan in later weeks.

It’s also a good idea to train as much as possible in the conditions you will race in for the best race experience.

50k Training Tips

Ultramarathons are growing in popularity, which means you’ll have an easier time finding races now and people who have been there done that to share tips! The number has surged from 103 races in 1996 to 1,500 in 2016.

Though the 50K is just over 5 miles longer than a marathon, they are different races and therefore require different training approaches.

Here we’ll break down how training for a 50K differs from the marathon.

1. More Slow and Steady Miles

Trail races differ from road races in that the weather can change in an instant, the terrain is more technical, and elevation profiles will constantly force you to alter your speed.

Run by effort, not by pace. (checkout running RPE to understand this better)
You’ll find that your 50K pace will tack on several more minutes to your per mile pace.
Don’t freak out, this is normal!

Where most marathon training plans include speed work in the form of tempo runs or track workouts, you’ll find that ultramarathon plans don’t focus so much on speed, but rather time on feet.

Ultramarathons can take anywhere from 5 to more than 20 hours, depending on the distance.

The real priority is learning to sustainably manage a consistent pace over that many hours.

More time running hills, including hill sprints early in training
More runs focused on time than distance (you should expect trail runs too take longer to cover a distance than on the road)
Working on your mind to enjoy being out there for that extra time
Testing great trail shoesto find ones that provide enough cushion for the duration and space for feet to swell a little
Practicing navigation skills that keep you from spending too much time searching for trails
Learning to power walk uphills to save energy

On steep hills, you’ll travel just as fast sower hiking as you would running, and it preserves energy.

Even elite athletes walk on hills!

Get 1-1 Ultra coaching from Coach Laura. She’s done Rim 2 Rim many times, along with over 20 other ultras and 40 marathons injury free.

2. Back to Back Weekend Long Runs

Most ultrarunners incorporate back-to-back long runs as part of their training plan. Rather than run multiple super long runs over the course of a few weeks, the idea is to split up the mileage to minimize the risk of injury.

Training your brain and legs to run when tired
First run will be the longer of the two runs.
Use the first run to focus on downhill technique, hills, or pace, while you’re fresher.
The second run is strictly easy miles and could be anywhere from half the miles to equal the distance of run 1.

If you have a busy schedule and can’t run all of that in one go, then break up the miles. Your 20 miler could look like 12 in the morning and 8 in the evening.

I’ve talked about splitting the long run in marathon training and the same things apply here, you have to know that doing it consistently could hurt you on race day, but once in awhile is fine.

The back to back long run may seem daunting at first, but you’ll be surprised at your body’s abilities.

Here’s how to make the most of back-to-back runs:

Active recovery: Limit sitting, foam roll, do post run stretches to keep the blood flowing throughout the day.
Get plenty of rest to enhance recovery
Choose a great post run meal to help your body – sure, have an extra slice of pizza and a pint of beer, but just not too much, ok? You still have to run the next day.

3. Course Specific Training

If you’ve ever looked at a trail race elevation chart, you’ll notice right away that they look a little scary. Some make you think that you’re about to tackle Mt. Everest.

Often, they’re scarier than they look, however it’s important to realize that trail running includes far more hills than road running.

Study the map and learn the grade and length of the hills.
Take note of the total elevation gain and model your training for those specific statistics.
Practice similar grades and lengths to build your stamina and practice power hiking.

If you live in a flat area (and even if you don’t), incorporate this 3-minute “mountain legs” routine by ultra running coach David Roche. He suggests performing it three to four times per week after runs.

Want more guidance, but not up for the cost of 1-1 coaching?

✅Checkout our Trail and Ultrarunning course.
It includes, how to run with poles, how to run in different weather conditions, how to stay safe, how to fuel and so much more.

4. Strength Training for Ultrarunning

As with any running distance, I can’t stress the importance of a strength routine enough.

Running a 50K means spending a lot of time on your feet. You need your muscles to stay strong when the fatigue sets in, otherwise you’re headed for many common running injuries. Which means, no training and no race.

Focus on building a strong core, building glute strength, and hip stabilizing exercises. Here are a few strength routines to get you started:

Complete Runner Strength Training Programs from bodyweight to heavy lifting
Stability ball core workout
Resistance band workout for glutes and hips
Hip mobility drills
Upper body strength for runners — this will help you power up hills

5. Recovery is Key for Ultrarunners

The more you exercise and wear down your muscles, the more recovery time you’ll need to repair them. Which is one reason we don’t ask you to do long runs that are 30+ miles until you’ve started to look at hundred mile races.

Think of recovery has part of training. It’s got a number of components: healthy eating, massages, Epsom salt baths, plenty of restful sleep, and both physical and mental rest.

And recovery is especially crucial for ultrarunners. This is because the damage done to your muscles over the course of an ultramarathon is more than the damage done over the duration of a marathon or a shorter race.

And if your race is on the trails, your muscles will be even more tired, especially because that means you’re probably training on the trails as well which simply require more energy due to the terrain.

Maintaining a fit and healthy body takes time and cannot be rushed, so don’t overdo it when training for a 50K.

What to Eat During a 50K

Ask any trail runner and they’ll tell you, without hesitation, that trail races have the best aid stations. They’re stocked with delicious foods like fruits, PB&J, chips and candy.

SO MUCH CANDY.

While ultra runners certainly rely on gels and chews like road runners, they tend to fuel with whole foods during training and on race day, thanks to the lower effort compared to a marathon they’re able to digest these foods without stomach distress.

Bring potatoes in some form as fuel, is SUPER COMMON. They’re easy to digest, full of nutrients and nice when you get tired of all the sugar.

You’ll be out running for at least five to six hours, if not more for a 50K, which means you’re burning a ton of calories that you need to replenish during the run. This is the exact reason energy gels and bars were created.

Plan to consume 250 to 300 calories per hour. — Note this is standard advice, but I often find it’s too much food for many runners and instead staying consistent with hydration, a great pre-race meal and 100 calories an hour keeps them going with less gastric issues. You Have to know your body.
Aid stations are few and far between on trail races, so go prepared with your nutritional and hydration needs.
Test out potential foods during training by checking the race website to see what they stock at aid stations.

Check out these great running hydration vest, including the one I’ve used for years, to find one that let’s you carry all the things you’ll need besides food!

Choosing Your First Ultramarathon

Race Reputation

Look for a race with a fun and supportive atmosphere for the best race experience. Be selective about which one you want to run so you can have a good time. This can also help a great deal on race day itself.

Altitude

Figure outthe beginning point and overall altitude of the trail you race you’ll looking to run.

As a runner, you might have trouble if you race at a higher altitude than you are usually used to.

Elevation Gain

The elevation gain and loss in different racesmight vary significantly. Trails with large elevation gains are more difficult for new runners and a significantly tougher endurance test than relatively uniform tracks.

Course Structure

The structure of the course on which you intend to run can range from a narrow, rocky single track to a large, groomed trail, and runners should evaluate which best matchestheir level of training and physical health.

Temperature

Choosing the right time of year for your 50Krace can make a big difference in how well you do and the sort of temperature you’re likely going to face.

Extreme temperatures are hard for any runner, but especially for those who are new to trail running.

Aid Stations

Remember how I mentioned how good the aid stations are in 50K? Well, some races with more remote trails have fewer aid stations since they are not designed for huge numbers of participants.

Consider how many aid stations there are in your chosen raceand what they offer in terms of water, food, electrolytes, and toilet facilities.

Cut-off Times

Look for a race with generous cut-off times, especially if this is your first time running a 50K.

As you can see, finding that perfect first race may take a bit of research. Ask friends who have run ultras or your local running store which races they recommend in your region.

Starting with a race close to home will relieve you of the added stress of travel and you may be able to convince a few friends to come to support you for your first ultra.

But…

A destination race could be fun, too. If this is your choice, then just factor this into your mental training.

If you’re looking to figure out how to find the right ultramarathon coach, then you should check out my friend Heather’s post where she goes in-depth into exactly how to do that! I highly recommend checking that out.

50K Gear Essentials

Having the right kind of gear during your 50K can be incredibly important. It’s going to be a lot like your marathon gear, but let’s look at some of the key considerations:

Fuel and Hydration

As I mentioned above, plan to consume 250 to 300 calories per hour. Bring a mix of fuels like energy gels and chews with you. Have a good hydration pack on to store it all and give you access to water whenever you need it.

This also means that a higher level of calorie consumption compared to a marathon means you’ll have to eat often so that you don’t get exhausted too quickly.

So keep options around, especially ones you have already tested during training and that haven’t bothered your digestive system at all.

Chafing Cream

The last thing you want on race day is to experience chafing. So keep some chafing cream around to help whenever you feel any irritation.

Sun Protection

You’ll be outside for quite a while so make sure you have some good running sunscreen on you, along with protective gear like a running hat to protect your face.

Right Shoes

Make sure to find the right running shoes for your particular 50K trail and practice in them. Get two pairs that you alternate with

I cover in depthwhy you need to rotate running shoes, but you should have a minimum of two to three shoes for ultramarathon training.

Comfortable Clothes

Wear something that fits the weather conditions you’ll face and that’s also comfortable when you run. The last thing you want is for those shorts or shirt to be distracting you on race day.

Beginner-Friendly Ultramarathons

There are plenty of 50K races across the country that are beginner friendly. What that means to us is longer cutoff times, less competitive atmosphere in many cases, less vertical and pacers allowed.

Are these the easiest 50K races? I’m not sure that exists, unless you do a solo ultra like I did and choose your own course on the day the weather is best!

Here are a few to check out:

Pacific Northwest Ultra marathons

McKenzie River 50K, Central Oregon

Oregon’s oldest ultramarathon follows the beautiful McKenzie River, featuring waterfalls, lava flows, old growth forest, and the famous Tamolitch Pool with deep blue waters. The trail is known as one of the most beautiful in the country with a net elevation loss of 3,328 feet.

Rainshadow Running, Washington, Oregon

This NW-paced race group hosts over 10 races in some of the most beautiful spots around the Northwest, including the San Juan Islands and the Columbia River Gorge. Many even allow dogs, so if your dog is your training partner, they can join you!

Daybreak Racing, Washington, Oregon

Relatively new on the ultra scene, Daybreak Racing events host some of the most beautiful and fun races in the NW. Race Director Jeremy Long puts on fun and inclusive races with high quality swag with a focus on safety and organization.

Mountain West Ultramarathons

Golden Gate Dirty 30 50K, Golden, CO

While this Colorado race isn’t easy, this one is all about the experience and the views. The Dirty 30 welcomes newbies while also still caters to elite athletes. Most importantly, the woman-led race recognizes the barriers women face in a male-dominated sport, and encourages women to participate, by reserving 50% of spots for women.

Aravaipa Running Races, Arizona

Aravaipa is best known for the Javelina Jundred, a 100-mile race that is beginner-friendly. They also host several other races in Arizona, with a focus on community. The organization hosts weekly group runs, both on the track and on the trails.

Midwest Ultramarathons

Ice Age Trails 50K, La Grange, WI

This is your chance to participate in one of the longest-running ultra marathons in the country, going strong since 1981. The course winds through natural features left behind from the glaciers that retreated over 10,000 years ago.

East Coast Ultramarathons

The Georgia Jewel, Dalton, GA

Runners can choose from 35, 50, or 100 mile distances in this rugged trail adventure. Georgia’s longest-running ultra features stunning Appalachian ridgelines and a rock garden that will give you a new appreciation for rocks…or not. The finish line boats a fun and energetic atmosphere.

Finger Lakes 50K, Hector, NY

Located on a network of trails outside of Ithaca, the course is a 16.5-mile loop that runs through the Finger Lakes National Forest along a mix of single track, paved and dirt roads, and pastureland. The best part about this race is that many participants camp out together the night before the race.

Road Ultramarathons

If you want to stick to the road, but still want to tackle an ultra, there are a few races out there for you. Be warned, some of these are very tough races!

Comrades Marathon (55 miles/89km) in South Africa is the largest and oldest ultramarathon race in the world
Badwater Ultra Marathon – I mean it doesn’t get much more intense!
Self Transcendence Ultra is 52 days running 3100 miles around a city block
Ok so basically it’s starting to look like you need to be extra crazy to do a road ultra, but I didn’t feel that way doing mine, ha!!

Solo Ultramarathon

Personally, I wasn’t interested in the worry about will or won’t a race happen right during shut downs.

I also knew that this was all about me seeing if I could go the distance, so I was ok treating it like a long run without any major fan fare.

I left the house alone about 5:30 in the morning
I took off running on the roads with a good plan of where I was headed
Miles 1-19 were incredible and joyful
19 suddenly I had a severe and sharp right knee pain. I was struggling to walk and willing to call it a day over causing major injury.
I called my husband to meet me around mile 20 and I kept walking. There I changed shoes and gave myself a little pep talk that I would just take a few more steps and see what happened.
Within about 1/2 mile I was slowly running again.
Within a mile the knee ached, but no longer hurt and I knew I could keep going.
We shifted the plan from continuing on the road to a nearby lake that had some crushed gravel.
David met me there and around mile 28 he was becoming my I think I may have to just walk with you buddy.
Mile 30 hit and all those endorphins came back so I managed to run the full last mile.
Finished in 6 hours and 15 minutes, which wasn’t my original goal, but considering the pain, the solo day and the air quality from fires…I was SO FREAKING PROUD.
I’ve never cried that hard finishing a race, what a mess.

I’d like to try this again and see if I can do it pain free. SO who knows what next year will bring.

Looking for more Ultrarunning content?

What I learned running my first ultra (a guest post)
Explore our Trail and Ultra running course
Checkout our newest running coach, who is all about the ultra!

Other ways to connect with Amanda
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