Ultramarathon Training Runs Explained

Training for an ultramarathon requires a totally different training modality to shorter races like half-marathons and marathons.

Once you get into races that are 50km, 100km, or 100 miles long, your focus has to change.

Instead of training for one concentrated burst, you have to train your body to be an endurance monster. You should prioritise building endurance over building speed – successful ultramarathons are not about being the hare, but the tortoise.

Steady, conservative, and consistent.

This means building up a solid running base, then getting used to running for several hours at a time – all while avoiding injury. 

Only once you get comfortable at ultra-distances should you begin to focus on pace.

In this post, we’ll look at ultra-marathon training for three different profiles: Beginner, Improver, and Advanced.

Your training will be dictated by the length of your race, your current fitness levels, and your goals. 

Remember that every ultra runner is only as good as their training plan – check out my ultramarathon training plans here, they’re free to access, download and customise.

Ultramarathon Training Runs Explained 1

Ultramarathon Training: Long Runs

Long runs are where you build endurance, plain and simple.

They are where you work on both aerobic ability and muscular endurance

They also allow you to get used to running long distances – you get experience working on your pacing, your fuelling and hydration strategies, and also the mindset of running for hours on end.

A typical ultramarathon training plan will feature a weekly long run, gradually increasing in distance.

Related: How To Go From Marathon To Ultramarathon

Long Run Pace

If you are a Beginner or Improver ultra-runner, your Long Run pace should be slow and steady. I’d encourage you to not even track your running speed – instead just get those miles in.

Ultramarathon training is all about getting you used to spending hours and hours on your feet, and that’s what the Long Run is all about.

If you do have any specific pace ambitions, I’ll discuss how to implement them into your shorter training runs – just don’t try and run your long run at your target race pace.

This is a common mistake amongst distance runners . . . it means you’re not training for endurance effectively, and often doesn’t do much for your pace either. It also increases your risk of injury, burnout, and fatigue.

Advanced ultra-runners can and should track their Long Run pace. Once you’ve got several ultra-distance events under your belt, your body will have adapted such that you can usually safely do Long Runs at a more challenging pace.

How Long Should My Long Runs Be?

A perennial topic of discussion for ultra-marathon runners is how long your long runs should be.

In shorter distance events, such as marathons, it’s common for your long runs to max out at around 75% of your race-day distance. However this approach is untenable once you get into ultramarathons.

For Beginners and Improvers, most running coaches agree that there is little benefit in running more than 30 miles. Once you cross the 30 mile mark (or say 5 to 7 hours on your feet), things get a little harder to recover from. There’s little incremental gain to be had, and you’ll encounter more and more signs of over-training; stubborn minor complaints, fatigue and lack of energy, delayed recovery time.

Back-to-back running days are an effective method of piling on the mileage without overdoing it on the long run – try adding on a training run the day after a long run.  Your legs will be stiff and tired, but will soon loosen up. It’s a way of training your body to run on tired legs which is popular with ultra-runners.

Advanced ultra-runners often look to supplement their training with other races- running a 50 miler while in training for a 100k, for example.

How Quickly Can I Ramp Up My Long Runs?

Assuming that you’re coming to ultra-running with a solid running base, you can apply the 10% rule – which says your total mileage shouldn’t increase by more than 10% each week. It’s meant as a rough guide, but it will give you some structure and keep you from overtraining.

A note on step-back weeks: every 3-5 weeks you should run a shorter long run, say 75% of the previous week’s distance.  These ‘step-back’ weeks allow your body a short reprieve, during which time it can recuperate a little and consolidate the gains you’ve made in the prior weeks.

Ultramarathon Training: Regular Training Runs

A training run is a short-ish run (4 to 10 miles) done two or three times per week.

The purpose of these runs is to add to your weekly mileage, have your body continually get used to running, recover from speed work/long runs, and (potentially) work on your pace.

These runs are handy for squeezing in quickly in the morning or after work – they’re the bread-and-butter miles of any good training plan.

Training Run Pace

Training runs have no hard-and-fast rules about pace.  They often are performed as recovery runs after a long run or speedwork day, so don’t be too uptight about maintaining a specific pace during every training run.

Generally, you should look to run a pace which is sustainable, but slightly challenging.

Beginners should do their training runs at a pace they feel comfortable with.

Improvers, especially those with a target finishing time in mind, should generally look to run their training runs at their target race pace.   This gets your body used to running at this pace.

Advanced runners should also be doing their training runs at their target race pace.

Training Run Length

Your Training Runs will typically vary in length between 4 and 10 miles, depending how deep into your ultramarathon training you are.

Even if you’re in a high mileage week, it can be useful to slot in a short 5 mile recovery run after your long run day.

Ultramarathon Training Runs Explained 2

Ultramarathon Training: Speed Work

Alright, first off, a word about speed work.

You don’t need to do any speed work in order to sufficiently train for an ultramarathon.

This is especially true for Beginner ultra runners; your entire focus should be about endurance (building time on your feet).   If you try to introduce speed to your training you’re increasing the risk of injury and fatigue.  You really want to have a pretty solid ultra-running base before you start to even think about speed work.

For Improver ultra-runners, you may wish to introduce one speed session per week. These sessions help to improve your running economy (i.e. your personal ‘miles to the gallon), will increase you base running speed, and can be fun to mix up your training.

Advanced ultra-runners, especially those with a time goal for their event, should incorporate speed work into their plan. I generally recommend no more than one speed work session per week; any more and you will struggle to recover fully and therefore not realise the gains effectively.

Let’s look at the different types of speed work, and how to implement them:


Interval training is a simple and fun form of speed work. 

Run fast for a few hundred metres, then run slow for a few hundred metres. Repeat.

How long should your intervals be?

Aim for 800m – run 800m fast, then 800m slow

Start off with 3 repeats of this routine, and then over the weeks gradually build to a maximum of 8-10 repeats.

‘Fast’ pace intervals should be done at a near-unsustainable pace – push yourself to keep the tempo up during those 800m.

‘Slow’ pace intervals should be done at an easy, forgiving pace – try to keep running or jogging, but don’t worry about speed!


‘Fartlek’ actually means ‘Speed Play’ in Swedish, and this is basically what you’re doing.  

Fartleks are like a free-form version of intervals – you run fast for a bit, then take it easy for a bit. Essentially you mix it up in order to vary your heart rate and training intensity.

If you’re a trail runner, you’re probably already doing some form of Fartlek training in your regular runs – as the hills and climbs of the trail vary, so does your intensity.

I don’t prescribe Fartleks too much, as it is difficult to define or measure the intensity level of the run.

However, if it sounds like fun to you, go for it!

Hill Repeats

Hill repeats are a speed exercise I normally reserve for Advanced ultra-runners, simply because of the strain they put on your body. They take longer to recover from and have a higher risk of injury. They are, however, awesome at strengthening your legs and boosting your endurance.

How to perform hill repeats?

Find a hill or section of a hill that takes 45-60 seconds to climb; it doesn’t have to be too steep, just a gradient that is going to challenge you.

Starting at the bottom, go hard and push yourself up to the top of the hill – try to keep a running gait throughout. 

At the top, turn around and very slowly saunter back down. At the bottom, pause and collect yourself before repeating.

Try to do this 8-10 times on your first session.

As you improve, you’ll find you can reduce the pause between hill repeats.

Ultramarathon Cross Training

Just as important as any run workout is your cross-training – that’s why all of my training plans include at least one cross-training session per week as standard.

‘Cross training’ means any form of complementary exercise which doesn’t involve running. It is a huge field, so I’ll walk you through my recommendations.

The most effective forms of cross training are those which directly complement and improve your running performance.

Gym Work / Strength Training

Strength training is my favourite type of cross training.   The reason is that it makes you a more powerful runner and can strengthen the areas typically weakened by long distance running, cutting down your risk of injury.

Whether you’re going to the gym, doing circuit classes, or simply some body weight exercises at home, including one strength training day per week will pay off dividends come race day.

I focus on exercises which target the lower body, the core, or which work out the full body.

Examples include:

  • squats (can be bodyweight only)
  • push-ups
  • deadlifts
  • hip mobility stretches
  • lower body resistance band work
  • pull-ups

Yoga and Pilates

Yoga and pilates are awesome forms of cross-training, simply because they target the muscular imbalances caused by running, and focus on flexibility.

Running is a pretty unilateral movement, which leads to some muscles becoming strong while others are neglected and weaken. This creates an imbalance in your kinetic chain, which often leads to injuries such as Runner’s Knee or hip problems. 

Yoga and Pilates are both awesome at reducing this risk!

Related: What To Wear To Yoga Class


Swimming is a good form of cross-training – it’s very low-impact, you stretch out naturally as you swim, and the gentle water pressure can be relaxing for your body.

It’s also an awesome form of cardio. 

You can choose to use swimming as a form of cross-training (I recommend throwing in some breast stroke – those frog kicks really open up your hips!) or for relaxing and recovering on a rest day.


Many runners are also avid cyclists, so like to jump on the bike on cross-training day.  Cycling can help improve your running economy, but is unlikely to decrease your risk of injury – so unless you’re already into bikes, I would recommend picking another form of cross training. 

Photo of author
Thomas Watson is an ultra-runner, UESCA-certified running coach, and the founder of MarathonHandbook.com. His work has been featured in Runner's World, Livestrong.com, MapMyRun, and many other running publications. He likes running interesting races and playing with his two tiny kids. More at his bio.

3 thoughts on “Ultramarathon Training Runs Explained”

  1. This is so reassuring and helpful. Signed up to a 52k and never done anything like this before…not even a marathon! Always run but furthest has been 15 miles (a few years ago) as been recovering from injury.

    Glad to hear that what I have been intuitively doing is ok. Just hope I can keep it up… and slow down!


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