Training: Ultramarathons

trail runner on the north coast of jersey

In this training article we go long – very long! – and look at how to train for an ultramarathon running event.

What is an ultramarathon?

An ultramarathon is any race or event longer than a marathon.

With no upper distance limit or stipulations on terrain within that definition, that leaves a practically limitless array of possibilities. Many ultramarathons tend to stick to round numbers, such as 50km, 50 miles, 100 km or 100 miles. However, there are many events that deviate from this format, for example:

  • Self Transcendence 24hr Track Race: A full day of running as many laps of a 400m athletics track as you can.
  • Comrades Marathon: Approx. 89km between Durban and Pietermaritzburg in South Africa.
  • Petite Trotte à Léon: A ridiculous 300km long route in the Alps, with 25,000m of ascent, taking the best part of a week to complete.

Provided it’s clearly longer than the 26.2 miles, or 42.195km, of a standard marathon, then it’s an ultramarathon. It’s both as simple, and as complicated, as that.

How to train for an ultramarathon

Because of the range of events that fall under the ultramarathon banner, we’re not going to provide a detailed training plan, or look at event specifics as per the other training articles – as it would be impossible. Instead, we’ll provide some principles you can use to guide your own training.

Step one

This applies to training for all running events: Think about the demands of the event. What preparation will those demands require?

Factors to consider include:

  • Distance;
  • Terrain;
  • Weather;
  • Supported or self-sufficient;
  • Navigation requirements.

If it’s “only” a 50K on flat roads, then a marathon training plan might suffice – just with the long runs extended out slightly.

If the event has a lot of hills, then you will need to do a lot of climbing in training. For mountainous races you may want to take inspiration from (probably the greatest) trail ultramarathoner, Kilian Jornet, and measure your training runs by the amount of metres you gain in elevation, rather than distance travelled.

If the temperature is likely to be an issue, how can you prepare? For a race in a hot environment, you may want to try hot yoga, running with extra layers on, or putting a treadmill next to a radiator. For cold climates, you can prepare by taking cold showers, wearing an ice vest, or running at night when it’s cooler.

If you are required to carry all your food, drink and spare kit, rather than rely on aid stations, you’ll need to prepare for doing so.

If you are expected to navigate in unfamiliar terrain, do you have the skills to do so?

Each ultramarathon will have its own set of challenges. By identifying what they are, you will know what to focus on in training.

Step two

Once you know what the race is going to require of you, the second step is to honestly assess where you’re at currently. That will give you a sense of the scale of your task.

For example, it’s not an especially big jump for a seasoned marathoner to take on a 50K race. On the other hand, a runner who has just completed Couch to 5K is going to need to get a lot of training in before they’re ready for the same event.

It’s not impossible for a new runner to eventually run an ultramarathon, but it is important to recognise where your strengths are, and what you are going to need to work on. This will help you design an effective training plan that is personalised for you and your circumstances.

Lonely Goats, Lisa Rodway and Ian Shearer at The Salisbury 54321
Long run length

How long should a long run be for an ultramarathon? Broadly speaking, there are two schools of thought:

“20-25-ish miles is enough”

Any more than that and the amount of time needed to recover will negatively impact on the rest of your training. Plus, go much beyond the marathon distance and you increase the risk of getting injured.

To make the long runs harder, you can always do back-to-back long runs on consecutive days.

“Don’t be afraid to exceed the marathon distance”

Logic suggests that if you want to run a very long way, then you need to run a very long way in training. That might mean doing a 50 mile long run to train for an 80 mile race, for example.

If you take it slow and allow lots of recovery time – such as a fortnight between long runs rather than a week – then the risk of injury is reduced.

The correct approach is going to vary from runner to runner, but may well involve a combination of the two. For example, if you’re going to do a very long, slow run one weekend, then the following weekend could be slightly shorter and quicker.

Is there a need for speed?

Beyond the élite level, ultramarathons tend to be run at a relatively slow pace. This is because they require runners to spread their effort out over a long time and not push too hard, too soon. Therefore, the need to include intervals, tempo runs and other speedwork in your training is less than it would be for a 5K, for example.

However, there is still a benefit. Fast running uses your muscles in a different way, which can improve your overall conditioning or let you dig deeper when the going gets tough. Plus, it can help break up the monotony of always running at an easy pace, which will keep things interesting and help you get through the long training plan.


Whatever the race distance, easing down on the training volume is crucial for consolidating the effects of your training, and getting to the start line with fresh legs.

For a 5K, you might only need a week’s taper. A marathon might require 2 to 4 weeks. An ultramarathon could need more than that, depending on how hard you have been training and how hard the race is going to be.

There’s no set formula to follow, as every runner is different, but it is almost always better to err on the side of caution and get to the start slightly undercooked, rather than overtrained.


Obviously, shoes that fit well and feel comfortable are essential. Likewise, you want to wear clothing that you know won’t cause you any problems.

You’ll probably have to carry a fair bit of stuff with you. Even races with aid stations tend to ask that you don’t rely on them for food, and stipulate that you carry a mandatory amount of kit for safety. To avoid carrying unnecessary weight, take the time in training to fine tune your kit list and get used to running while carrying it.

Races with bag drops, or the option to set up a personal base camp (looped courses, usually) still require planning and practice to get your logistics right, for your best chance of success on the day.

On a similar note, make sure you know how to treat blisters!

Food and drink

In some respects, fuelling for an ultramarathon is easier than for shorter events. In a 10K or half marathon, for example, you might be trying to squeeze a gel from a packet while running fast.

An ultramarathon is usually run at a slow enough pace that you don’t have to resort to gels or other, sticky, gooey, sweet things. Instead, you can eat and digest relatively normal food without as much risk of throwing it all up soon after you’ve eaten.

You’ll need carbs, sugar and salt – and protein won’t hurt – but you can be flexible as to how you achieve that.

As always, keeping topped up with water (little and often; drink to thirst) is important, but so is topping up your sodium to avoid hyponatremia.

Lonely Goat, David Sweeney at the Donnersberg Trail Ultramarathon
Go long!

Ultramarathons are some of the most complicated events to train for, simply because there is such a variety of events and different ways to train for them.

Some runners are better served by a slightly heavier volume, marathon-style training plan. Others will need to head out into the hills for hours at a time.

Some general guidelines are to:

  • Think about the demands of the event, assess your current state of fitness, and work out what you can do to bridge the gap between the two.
  • Listen to your body and try to work out where your limits are without exceeding them.
  • Simulate the conditions you can expect on the day of your event.

Also, remember that there is an amazing, helpful community of Lonely Goats out there you can ask for advice. There will almost certainly be someone who has been in a similar position to you and is willing to share their experience.

Check out the Facebook Chat Group, Strava Club, or tag us in on Instagram.

Above all, embrace the unique challenge of an ultramarathon, and enjoy yourself.

The Lonely Goat running training series

Check out the rest in this series of training articles…

…plus our other articles on different aspects of running training.

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