Training for a 50K or a 50 Miler for marathoners

Training for a 50K or a 50 Miler for marathoners

So you’re a bit bored with racing marathons?

Want to step up and try a new distance?  How do you go from 26.2 to 30 to 50?

My disclaimer here is that I am not an ultrarunner per se.  I have and do run ultra-distances.  I’ve never gone more than 50 miles.  I know I could do a 100 miler on foot, but I have no desire to.  Maybe someday I will.  I think my basic aversion to going super long is the time it requires.

I have run the difficult Vermont 50 miler.  I think I did it in just over 9 hours, which I understand to be a decent time for that race.  I can tell you how I trained for it and why.

I have friends who ask me how to train for ultras.  Specifically, how to step up from a marathon to an ultra-distance.  I’m going to tell you how I did it.  You can decide if that makes sense for you.

My summary would be that stepping up from a road marathon to a 50k is a pretty small step.  If you take one or two wrong turns in a marathon you’ll get that extra 5 miles.  Not a big leap.

Stepping up to a 50 miler is, again, quite manageable.  It’s double the distance but the intensity is much lower.

If you are rolling out of a qualify marathon cycle you should have no problem running a 50k.  You can also use that fitness to get to 50 miles in one training cycle.

The challenge:

But there are some things to consider…

Trails vs roads

Racing a road marathon is an entirely different beast than running an ultra-distance race.  It’s not just the distance and time.  Typically, these ultra-distance events are mostly trails with varying degrees of difficulty.

If you’re not a trail runner, the simple fact that the race is on trails makes it 20-40% longer and harder.  If you are moving up from a road marathon to a trail 50k you’re going to have to learn how to run on trails versus roads as part of the bargain.

Slowing it down

Moving up to the ultra-distance means you must learn how to slow it down.  I used to joke that if I was running a 3-hour marathon then a 50 miler would take me 6 hours, right?  Wrong.  You can’t, or at least most humans can’t, hold a race pace effort over difficult terrain.  You have to figure out a pace that you can maintain for twice as long as you would in a road marathon.

You have to take your available fitness and figure out how to spread it out over the distance and time of the ultra.  That means learning to slow down.  How much slower?  Typically 2 full minutes per mile slower.  This also means learning how to strategically hike.

Learning to eat.

In a marathon you can manage your nutrition to have peak energy throughout the race to support your pace and effort.  You can supplement sugar to keep your fires burning.  If you’re fast enough you don’t dip into your fat stores that much.

In an ultra there is no way to burn purely sugar.  Your body has to learn to burn fat.  You still need calories.  You have to train your body to eat while running.  I don’t mean shooting a Gu.  I mean taking real food early and often.  The goal is to keep the calories coming in so that your furnace is always fed.

The summertime.

Many of the ultras tend to be warm weather races.  If you’re not a warm weather runner this can be a challenge.  You must learn to run in such a way as to keep your core temperature within reason. You learn how to keep fluids and electrolytes coming into your system.

Many ultras are lightly supported.  This means you must learn how to carry your provisions with you.  Can you run with a full water-pack on your back?  Can you run with 2 hand-helds?  These are skills you might need to learn.

Doubling up the abuse.

If you have issues with chaffing or blisters or injuries in a marathon those are going to be twice as bad in an ultra.  Foot care, or lack thereof, probably causes more DNF’s than anything else.  The combination of uneven trails, hot weather and mucky ground can cause your feet to get abused.

How do you train for this?

The summary is that while the distance is manageable, you also have all these little, ancillary skills that you need to pick up to make the ultra-distance successful.

The good news is that you can keep it simple.  Like everything else in our sport you can over-complicate training for an ultra.  It’s really not that difficult to figure out.  You just need to get more volume and learn how to manage some new skills.

If you look up the training plans on line or from the magazines you might end up confusalled.  I’m going to simplify that for you.  It’s not that difficult.

If you have trained for a marathon using an advanced plan of any kind you can use that same familiar cadence to train for an ultra.  In an advanced plan for a marathon, let’s say it’s a three-month plan.  In those three months, you will have a series of two or three week waves increasing intensity with step-back weeks to recover.

You can do the same thing to step up to an ultra.  Instead of speed and tempo during the week do other ultra and trail specific training, like long hills and doubles.  Instead of capping out your long run in the 20-24-mile range go up to 30 or 35.  Same cadence as a marathon plan, just modify the workouts.

For the weekly cadence, all I tried to do was to get more volume on the trails.  On Tuesdays and Thursdays, I’d do doubles.  Doubles are where you run twice in one day.  This is one way to train your legs for the volume of an ultra and to adapt to running on tired legs.

A double could be 5 mile trail run in the morning then another at lunch.  Or it could be run at lunch and then in the evening.  You’re basically trying to squeeze in more volume during the week.  I didn’t do any dedicated speed-work except for occasional long-hill tempo reps.  Either uphill or downhill, as part of a trail run.

A lot of the plans will have you doing back to back multi-hour long runs.  I found that to be just miserable and really increase injury risk.  Instead I took Saturday as a rest day and went super long and slow on Sundays.

The way I did this was all on the trails behind my house.  I have a nice 10kish loop with some decent elevation gain and a nice mix of technical single-path and double path.  That’s a good analog for most Ultras.

To teach myself how to slow down and how to eat I worked this into my 10k loop.

One of the ways to slow down in Ultras is to hike the uphills.  I say hike on purpose because it’s not a walk.  There is a specific mechanical action where you lean forward a bit, get low and swing your arms for momentum.  You are still moving at 3 or more miles per hour but you are using a different muscle set for this propulsion and your running legs get rested.

I would set my watch alarm to go off every 20 minutes.  Every 20 minutes I would walk and force myself to eat something and drink something.  Each time I came back to the house I could fill my bottles and keep going.

Using this methodology, I was able to work up to 6 loops of this 10k-ish trail course for my longest outing before I tapered into the 50 miler.  So somewhere between 30-35 miles over the course of a three-month cycle.  And that was plenty for the race.

I was also able to train my body to burn fat very efficiently, adapt to the long trail run in the summer, and eat and digest on the run.


You can step up from a marathon to a 50K or a 50-miler easily in a normal training cycle.  I found the training, in a way, relaxing.  Instead of intense speed and tempo training on the road I just did a ton of long, enjoyable miles on the trails.

It’s quite do-able, especially if you are exiting a quality marathon training cycle.  Just slow it down and have some fun.



  • Foti Panagakos

    Reply Reply May 15, 2017

    Thanks Chris. Great article. I ran one 50k at Cowtown. It is a road 50k, so for those looking to tackle that distance and staying off the trails, this would be a good race to look into. It is well supported.

    • cyktrussell

      Reply Reply May 15, 2017

      Thanks – there do tend to be some 50k’s that are road based. Like the JFK. or even Comrades. Totally different animal.

    • cyktrussell

      Reply Reply May 21, 2017

      I did a race in CT called Kettletown State Forest. I’ll write it up. The course ended up being a lot harder than a thought it would be. That being said, for some odd reason I felt great and had a super day. No issues. Since the Boston in April I’ve done a couple 2ish hour training runs but nothing serious – so stepping up, like I said is easy, as long as you are strategic about it and slow it down.

  • Mitchell Goldstein

    Reply Reply May 21, 2017

    I have begun thinking something beyond a marathon would be fun to try. 50k seems like a good distance to go to first. Foti — did you enjoy Cowtown?

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