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How To Run Your First 50K Ultramarathon (31.07 Miles)

Love a challenge? Try an ultramarathon. It’s a logical step up after becoming a marathon runner. Just 5 miles longer than a marathon distance – how hard can it be?

Well, that depends. Add 5 extra miles on a flat road course and most people will make it to the finish by digging a little deeper and adding a few more miles to their marathon training plan.

Enter an ultramarathon on the trails and everything changes. Welcome to my world of mud, sweat, and tears. You’ll need strong legs and ankles, knowledge of how to navigate and stay safe on the trails, a completely new running wardrobe, and a whole new attitude to race food.

So are you ready to run further?

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50K in miles

How Long Is A 50K In Miles?

50K is 31.07 miles.

Officially any distance further than a marathon is considered an ultra marathon, but 50K is the normal distance tackled by first time ultra runners.

Runners are always looking for the next challenge, so there doesn’t seem to be any upper limit to ultra-marathon distances. Only a few years ago typical long distances were 50K, 50 miles, and 100 miles but now running a 200-mile race is becoming surprisingly common!

But everyone has to start somewhere. If it’s your first ultra, start with 50K.

Stepping Up The Distance For Road Races

No one in their right mind launches straight into a 50K race on the roads without a background in distance running. It makes sense to have the experience of several half marathons and the standard marathon distance before taking on a 50K. Preferably several marathons.

Being able to run at a steady pace, follow a training program, and keep to a race plan, are all skills that will help you get to the finish line on race day.

first ultramarathon training plan

Run A 50K On Roads

To complete a 50K on a relatively flat course on the roads, all you need to do is add some extra distance to your marathon training schedule.

There are lots of different training plans for road marathons so I suggest you adopt a plan that’s already worked for you. You can adjust a marathon plan to a 50K training plan by adding 10 to 15% extra weekly mileage or training time. Add extra mileage to your easy-paced runs but make sure you’re still building your weekly mileage gradually and allowing for proper recovery. An alternative is using cross-training – this way you can increase the time you spend exercising without overloading your body.

Your most important session for any marathon or ultra training plan is always the long run. Typical marathon plans build up to running 22 to 23 miles before race day. For 50K training, I suggest aiming for 26 to 27 miles – it’s so much easier to run a 50K race if you know you’ve already got to within 10% of the distance during training.

Another good session is a long easy-paced run or even a run/walk based on your estimated total race time rather than distance. The aim is to adjust your body to the challenge of a longer race. Running longer without getting tired. It’s about time on your feet and helps build resilience to mental fatigue during the race.

Road marathon runners normally use shorter races such as a half marathon to help get race fit. For your first ultramarathon, try and find a slightly longer intermediate race – maybe a 15-mile or even a 20-mile race.

50K Ultra Pace On Roads

The aim of any road ultra on a flat course is to run at a constant pace but what should that pace be? Can you run at your typical marathon pace and just hang on in there for another 5 miles?

It’s best to be a bit more realistic and add 10 to 20 seconds to your marathon pace to comfortably run the extra distance. Of course, this will depend on your typical mile pace.

Elite athletes may cope with just a slight difference in pace, but for most runners, it’s better to run at a slower pace to make sure you make it to the finish. You can always speed up for your last 5 miles!

training for first 50K

50K Trail Ultras

If you’re a road marathon runner, approach trail running as a completely new sport. Even the name is misleading. On a steep hilly course, you’ll be spending some of your time walking!

It’s A Significant Challenge

Forget steady pace running, or target running times resembling your marathon time. A trail ultra can include steep hills, mastering uneven terrain and there can be long sections between aid stations. Some races even start in the middle of the night!

Instead of stuffing a few gels in your pocket, you’ll need enough calories and liquid for hours on the trail, plus clothes to cope with extreme weather conditions.

You might get lost!

There’s so much more to think about when you’re making the switch from road to trail races. Talk of minutes per mile goes out the window. You can’t even make direct pace comparisons between different 50K trail races. Elevation gain and rocky or boggy trails will dictate how fast you can run. So forget about pace and concentrate on getting around your first ultramarathon one piece

Train Specifically For The Trails

Complete all your training on the roads before showing up for a trail race and you’re going to suffer. (The reverse is also true – I find it very hard to run on the roads when I’m used to technical trails).

Trail running can be pretty tough on your body. Rocky terrain and slips on the trail can take their toll, so it’s important to make sure you prepare properly for a trail race. A lot of new trail runners suffer from weak ankles. Twist your ankle and it can take weeks or months to recover so take the time to work on your strength training.

Hills can come as a bit of a shock if you’re a road runner. Learn how to pace yourself up a steep climb – often walking is faster than trying to run when the gradient gets steep. You can build your leg strength in the gym but there’s no better way than training on the type of terrain you’ll encounter during your 50K race.

Find some other runners to train with and get used to running on uneven ground and clambering over natural features. Trying to run up steep trails certainly gets the blood flowing!

Training runs will mainly be about getting into the hills, running longer distances, and spending time on your feet. It can be about how many hours you’re out running rather than how many miles, especially for your first ultra.

While it’s good to keep your speed work up as part of the training process, most of your training will be long runs at a slow, easy pace. Incorporate walking into your training. Most runners will be reduced to walking at some stage on their first trail ultra – so train for it!

training for first ultra 50K

Train On The Race Course

If possible, try and get familiar with the race course. It helps to be able to visualize the course in your head, especially in the latter stages of the race when you’re getting tired.

By completing training on the course you’re building the leg strength you need to complete the race.

Equipment For Trail Races

Unlike a road race, you can’t just show up in your shorts and running tee. Just about all trail races have kit lists – equipment the organizers expect you to carry.

It starts with your shoes. There are specific trail running shoes for running off-road. Trail shoes should have good traction in both muddy and rocky conditions, a rock plate to protect your foot if you stand on sharp rocks, and sufficient support for contouring on uneven ground.

Clothing should suit the conditions but expect to carry full waterproof body cover – a running jacket and pants. You never know when the weather will change in the hills and it’s always best to carry spare layers. Longer races will expect you to carry survival bags, first aid kits, and even headlamps.

Most runners wear a hydration pack or race vest. It’s a good way to carry adequate fluids, snacks, and gels plus all your equipment.

Refueling On Race Day

Keeping your carbohydrate levels topped up is essential for ultra runners. After the first 60 to 90 minutes of a race, it’s suggested you consume 1g of carbohydrates per hour for every kilo of body weight. That’s a lot!

I use Sports In Science (SIS) electrolyte powder. It contains 36g of carbohydrate per serving, on top of providing all the electrolytes I need to stay hydrated. That’s about half the carb intake I need every hour on my longer runs. Read about supplements for endurance runners to stay in top shape during your long runs. Running in the heat can be a huge challenge at ultramarathons and every runner needs a strategy for staying hydrated.

Get the remaining carbs you need from trail mix, protein balls, energy bars, or gels. I find it helps to practice refueling on your longer training runs. Every trail runner has different preferences and you don’t know what you’ll want to eat after running 20+ miles until you’ve given it a try.

first ultra

Aid Stations

These vary considerably for ultra races. I’ve been in races with just squash and crushed biscuits while other aid stations think about every type of food a trail runner could possibly want.

If you’re a slower runner you can sometimes get a raw deal. Good race organizers will make sure there’s enough food left for runners at the back of the race. But sometimes it’s best to make sure you have enough of your own food just in case.

It’s All In The Mind

No one runs their first 50K and feels great all the way around. It’s as much about the mental challenge as it is about the physical effort. Tell yourself all you have to do is keep putting one foot in front of the other – and you’re on your way to becoming an ultra runner! A few motivational running quotes might help.

Often races don’t go to plan so be prepared to adjust your pace, maybe slow down for a while to let yourself refuel and rehydrate.

For your first ultramarathon focus on getting to the finish and enjoying the race experience. There’s more to ultra running than your finish time. Fresh air, beautiful scenery, new friends – you’ll be back for more!

Frequently Asked Questions

How many miles is a 50K run?

A 50K run is 31.07 miles. Officially any distance further than a standard marathon is considered an ultra marathon, but 50K is the normal distance tackled by first-time ultra runners. It can be easy enough to make the jump from a road marathon to a 50K road ultra but the transition to a 50K trail ultra is a lot harder. Expect long steep climbs, rocky terrain, and muddy bogs.

What is the average time for a 50K

For trail ultras, there’s no such thing as an average time. Each race is different – elevation gain and technical trails make some races much slower than others. For road ultras, your running pace will be about 10 to 30 seconds slower than your marathon pace. The average finishing time is about 4 hrs 30 but anything under 6 hours is good.

Is a 50K an ultra?

Yes! Anything over the standard marathon distance is considered to be an ultra. 50K is the shortest common distance for an ultramarathon.