By Marnie Kunz,
Certified run coach and trainer

If you’re wondering how far a 50K in miles is, and have other ultra running questions, this guide will go over all the basics you need to know. A 50K is 50 kilometers, which is equal to 31.07 miles. Running a 50K is often a gateway into the ultra running world, as it’s the first distance over a marathon before hitting longer race distances such as 50 miles and 100 miles. If you’re interested in running a 50K, this guide offers training tips to help you cross the finish line of your first ultra.

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Ultra Distances - 50K in Miles and More

So what is ultra running, exactly? Ultra marathon running includes race distances longer than the marathon, which is 26.2 miles (42.195 kilometers). Ultra races range from 50K to 50 miles, 100 miles, and even farther, multi-day events that can be up to thousands of miles. Ultras are run on a variety of terrain, with many on trails.

A 50K is the shortest-distance ultra race. The 50K in miles is equal to 31.07 miles, or 50 kilometers. A traditional road marathon is 26.2 miles, and a 50K is about 5 miles longer. The next most popular ultra marathon distances are 50 miles and 100 miles. There are also much longer ultras, with a total distance of 1,000 or more miles.

Training for an Ultra

If you have your heart set on running an ultra, you’re in good company as ultra running is experiencing a growing boom, with an increase in all participants, especially among women and middle-aged adults. According to RunRepeat, ultra-running participation has increased by 1676% in the last 23 years from 34,401 to 611,098 yearly participants and 345% in the last 10 years from 137,234 to 611,098. There have never been more ultra runners.

Training for an ultra takes time and dedication, making crossing the finish line especially rewarding. Here are the essentials of what you’ll need to train for an ultra marathon:

Gear

Since ultras are extra long-distance races and often done in remote locations on trails, you’ll need more gear and planning than you would for road races. Aid stations are often far apart in ultras, and when you train and race, you’ll need to carry your own gear.

A hydration pack, such as a running vest or backpack, is the best way to store your necessities on the run. A good hydration pack allows you to store your fluids, nutrition, and essentials, such as sunscreen on the run. You may have to try different hydration packs to find the one that is most comfortable for you and your training conditions.

50k-in-miles-checklist — Use this gear checklist for your running training.

I find hydration vests especially helpful for long runs as they carry my gels, water and electrolytes drinks, and other snacks. Some people prefer backpacks, which can work well as long as you don’t get back pain. If you’re looking for hydration packs, Saloman has excellent options and is a popular ultra runner choice.

Your most important piece of equipment will be your shoes. Go to a running or outdoor store to try on trail running shoes and find the best fit for you. Also, remember that feet swell over long distances, so you’ll need running shoes that are a half size larger than your regular shoes. Opt for trail running shoes with good lugs on the bottom, which will help your feet grip uneven terrain on the trails and prevent falls.

Running Fuel

Since ultras are longer than marathons, you’ll need plenty of nutrition on the go to fuel your miles. A good nutrition plan will include running fuel such as gels and chews. Most ultra runners also consume real foods during races, with carb-rich options like potatoes, chips, and sandwiches. Experiment with different fuel options during your long runs to find the ones that are easy to digest.

In general, you’ll need to take some fuel every 30 to 45 minutes during your long runs and races. The intensity of the run and the difficulty of the terrain will also determine how much fuel you need, as more challenging routes will burn more calories and spur frequent refueling.

Hydration

Staying hydrated is important when you’re training for an ultra as this can prevent urgent medical conditions like heat stroke and also reduce your risk of cramps and energy crashes. Pre-hydrate before your run and bring hydration on long runs to prevent dehydration.

For long runs or runs in heat and humidity, you’ll need more than just water to hydrate. You can use a sports drink or add electrolytes to your water to replenish the electrolytes that you lose through sweat. Carry water bottles or bladders in your hydration pack for fluids on the go. Sip your drink every 15 to 20 minutes, at a minimum.

Training Plan

Whether you’re running your first ultramarathon or tenth, following a training plan is crucial to build your endurance and prepare your body and mind for an ultra trail race. A good training plan should be designed by a certified run coach and it will help reduce your risk of injuries and keep you accountable in your ultra training.

If you need a training plan, check out our Runstreet Customized Training Plan, and I’ll be happy to create a personalized ultra-training program for you.

A smart training program will increase your weekly mileage gradually to help you reach higher levels of fitness while minimizing your risk of injuries. A central component of ultra training is long runs.

Long Runs

A weekly long run is the cornerstone of preparing for a 50K race. Since a 50K in miles is about 5 miles longer than a marathon distance, your training program will be similar to a marathon training plan with a few key differences. Since most marathons are road races and 50Ks are usually trail races, your running pace and terrain will be much different for a 50K than for a marathon.

50k-in-miles-long-run-tips — These long run tips will help you crush your miles.

When you’re following an ultra training program, your weekly long run will increase incrementally to build up to running 20 miles or more. For beginners, two 20-mile runs or 4 to 4.5 hours on the trails should prepare you for race day. Your longest run will depend on your fitness level and training schedule, but count on at least a 20-mile long run as part of your training.

Since long runs take a big time investment, many ultra runners do their long runs on Saturdays or Sundays. Choose a day that you have time off work so you can focus on your run and recovery. In general, you’ll be doing long runs at a relaxed pace. Consistency is crucial for ultra training so if you have to miss a workout, it’s better to miss a regular base run day than a long run.

Terrain

Since ultras are on trails, doing a regular trail run is critical for your success. Do some of your training on the trail where you’ll be racing if possible. You can also find terrain similar to your race course. Check the elevation gain of your race and then make sure you have hill training in your program to prepare to tackle the vertical gain.

Trail running also calls for different running shoes than road racing, so invest in a comfortable pair of trail running shoes for good traction and support on the trails. Trail running shoes have better traction on the bottom and more ankle support, helping your feet to grip uneven surfaces and stay stable. Running on trails is more challenging than road running, so aim to do regular trail runs to strengthen your legs and feet for your 50k race.

Weather

Another consideration with trail running is the weather conditions. Since you’ll have less infrastructure and more natural conditions in a trail race than a road race, you’ll need to prepare for the weather, which often includes weather changes. Wear a hat, sunglasses, sunscreen, bug repellent, and moisture-wicking layers to help you stay comfortable on the trails.

If you are doing a race in remote areas and the weather may get rainy or cold, you may want to carry an extra layer such as a waterproof jacket in your pack.

Hill Training

Hills are a central component of long trail races, so check your race's elevation gain and prepare accordingly. Your training plan should include hill workouts to strengthen your legs and body for going both uphill and downhill.

Runners often discount downhill training but over long distances in hilly and rocky terrain, your quads can be destroyed by the downhills. Doing some downhill training on different inclines can help you strengthen your quads. Strength training will also prepare you to better tackle hill running.

Related Post: Hill Running Guide + Sample Workouts

Strength Training

Strength training should be part of a well-rounded 50K training plan. Having a strong core and legs will help you tackle the challenges of trail running over 31 miles. Strength training will improve your balance, running form, and leg strength, helping you to become a better runner and reducing your risk of running injuries.

Related Post: 10 Best Bodyweight Arm Exercises

I recommend doing two strength training workouts per week as part of your 50K training program. You can start with bodyweight exercises like planks, push-ups, squats, and side lunges. Do two to three sets of 10 for each exercise.

Related Post: 5 Best Core Workouts for Runners

For more advanced strength training, you can do dumbbell exercises like dumbbell bench presses, tricep extensions, bicep curls, lunges with dumbbells, and squats with dumbbells. Core exercises should be a part of every strength workout you do, so include planks in your training.

Cross Training

Cross training for runners is any exercise that is not running. Adding some cross training to your fitness routine gives your body a break from the repetitive motion of running while still improving your fitness level.

Doing one cross training workout per week can help you become a stronger runner and more well-rounded athlete. Excellent cross-training exercises for ultra runners are low-impact activities like walking, swimming, cycling, yoga, and pilates.

Nutrition

Since a 50K in miles is 31 miles of running, your body will need plenty of fuel for race day and throughout your training. Carbohydrates are your body’s primary energy source for endurance runs, so make sure you eat enough carb-rich foods. Sweet potatoes, pasta, oatmeal, whole grain bread, brown rice, and quinoa are all nutrient-rich foods with lots of complex carbs to give you sustained energy on runs.

Here are some healthy eating tips to power your ultra training:

Eat regularly. Consume small, frequent meals and snacks throughout the day to maintain consistent blood sugar levels.
Choose complex carbohydrates. Opt for whole grains, fruits, vegetables, and legumes, which provide sustained energy and fiber.
Carb load before your race. In the week leading up to your 50k race, you may want to increase your carbohydrate intake to maximize glycogen storage.
Listen to your body. If you feel fatigued or have low energy, it may be a sign that you need to increase your carb intake.
Eat enough protein. Lean protein foods such as lentils, nuts, tofu, lean meats, eggs, and Greek yogurt will help with building and repairing your muscles after tough workouts.
Eat a pre-race meal. Experiment during training to find a good meal that works well for you before long runs. Eat a balanced meal 2 to 3 hours before the race that includes carbs, protein, and healthy fats.
Fuel consistently. Consume running fuel every 30 to 45 minutes during the race.
Experiment and find what works. Try different types of fuel during training runs to determine what sits well with your stomach.

Tapering

In the weeks before your 50k race, you’ll need to taper your training. This means you reduce your mileage in the weeks leading up to the race. For a 50k, start tapering 4 to 6 weeks before your race by reducing your mileage by 10 to 15 percent. In the 2 to 3 weeks before your race, reduce your mileage another 10 to 15 percent and add more rest days to your program.

Your training plan should only include easy, short runs in the week before the race. Make sure you get plenty of sleep and eat well during this time. Tapering helps your body recover from training and hit peak performance on race day.

Related Post: How to Taper Running

Train Smart, Run Well

A well-balanced training plan will help you get from start to finish on race day as smoothly as possible. If you need a training plan to help you run your next 50k, check out our Runstreet Customized Training Plan. For this program, I assess your fitness level, goals, and schedule and create an endurance and strength training plan to help you achieve your ultra running goals. Don’t be left struggling trying to patch together your own training plan - leave it to a professional running coach and personal trainer, and get the guidance you need to succeed.

Happy running to you! For more training tips and workouts, sign up for the Runstreet Wellness Wednesday newsletter and follow @Runstreet on Instagram.

Marnie Kunz is a NASM-certified trainer and USATF- and RRCA-certified running coach, a dog lover, an Akita mom, and the founder of Runstreet. She specializes in helping runners get faster and stronger and helping beginners elevate their fitness levels. She is based in Brooklyn, New York.

How Far is 50K in Miles? Ultra Running Training Guide