How I’m training for a 50-mile ultra marathon trail race

Amanda in the Marin Headlands during the 2012 TNF marathon

Amanda in the Marin Headlands during the 2012 TNF marathon

Six weeks from this Saturday, I’m racing The North Face Endurance Challenge GORE-TEX 50-Mile in California’s stunning Marin Headlands. I ran this same race in 2010, a few months after the Alaska-Yukon Expedition, and it will be my first ultra marathon since. With $30,000 in prize money for the top 3 male and female finishers, this event attracts a star-studded international field, and to be in the mix I’ll need to bring my best.

I’m not an expert in training for 50-mile ultra trail races — I’m not a running coach, dedicated student of running science, or even a professional ultra runner. Moreover, my ultra racing history is thin. (It does, however, have some highlights: second place in 18:17 at the 2008 Leadville 100, my first and only 100-mile race; a PR of 8:02 for Grand Canyon Rim-to-Rim-to-Rim, which is 42 miles in length and has 22,000 vertical feet of gain and loss; and a 20th-place finish in 8:08 at the 2010 Endurance Challenge.)

So unlike a more seasoned runner for whom a 50-mile race is fairly routine and/or for whom recent ultra finishes constitute training for the next one, I’ve had to spend some time in determining how I should best train. Here’s my approach:


Running to finish or to compete? I have finished ultras before, and I don’t need to pay a race entry fee and fly to California in order to finish another one. No, I want to compete. I’d be happy to finish in 7.5 hours (9 minutes per mile pace), which is usually good enough for top 30, and I’d be delighted with anything better. Whereas a “minimum training” program might be sufficient if I were just trying to get back into the ultra scene with a performance similar to 2010, or if I were just planning to chase cutoff times to the finish line, it won’t deliver the type of performance that I want.


Course stats. The course is 50 miles long, features 10,000 vertical feet of gain (and ditto for loss, so 20,000 vertical total), should take about 8 hours to complete, has a mix of fire roads and singletrack, and never strays more than 2,000 feet above sea level. I need to optimize my training for these features, especially the first two. An off-the-shelf training program for a generic race or for a different race — e.g. 50k or 100-mile, flatter or more mountainous, faster or slower projected finishing time, higher altitude, more or less technical trails, etc — will not prepare me as well.

Injury resistance. In a word, what’s the best training strategy for an ultra? Volume. There is really no substitute for lots of miles, lots of vertical, and lots of time on my feet. Of course, there is a cap on how much volume I can withstand before I get hurt, either due to overuse or to a fatigue-triggered accident. Thankfully, I’ve proven to be very durable and I have a deep base of fitness, so I can be more aggressive in my training than most.

Core training

It takes a lot of time and effort to ensure peak performance on race day. I’ve focused it mostly on four elements:

Summary of my training over the last 7 days. Data gathered by my Suunto Ambit watch.

Summary of my training over the last 7 days. Data gathered by my Suunto Ambit watch.

Distance. I’ve run 103 miles in the last 7 days. That’s a lot, but my two longest runs (26 miles each) were still only half of the race distance, and it only averages out to 15 miles per day. On race day, it’s irrelevant if I’m the fastest 15-mile runner — I need to be able to race 50. Over the next month, then, I need to continue to increase the distance of my long runs, with my longest ideally being 50+ miles. Alternatively or in conjunction, I can do multiple long-ish runs (25-35 miles) back-to-back. To avoid mileage volume that will inevitably lead to injury, I will run just a few miles on recovery days, or none at all.

Vertical. The course has 20,000 vertical feet of gain and loss. In comparison, it’s a 14,800-foot round-trip between the summit of Pikes Peak and Manitou Springs, a 12,200-foot round-trip between the summit of Mount Whitney and Whitney Portal, and just a 9,500-foot round-trip between the summit of Mount Washington and Pinkham Notch. For this race, vertical training is just as important as horizontal/mileage training — if I ignore it, my quads will blow out early in the race and I’ll lose positions steadily thereafter. In the last week, my cumulative vertical was 25,000 feet and my biggest day was 6,000, or less than one-third of what I will do on race day. Over the next month, my vertical training plan is similar to my mileage training: continue to increase, with a maximum effort of at least 20,000 vertical feet in a single day.

Time on feet. This is one aspect of ultra training where I may have an edge on most everyone else. I have spent thousands of days on my feet, hiking at 3 miles per hour for 15 hours per day. For an 8-hour effort during which I hope to average 9 minutes per mile, this hiking history is probably not hugely advantageous. But if I were training for a longer and slower ultra (e.g. Hardrock 100) or if I were trying just to finish within the 14-hour cutoff, I would incorporate long day-hikes or even multi-day backpacking trips into my training program so that my body learns how to move slow and steady.

Extra body weight adversely affects athletic performance. This crew had little, and thus were able finish a super ambitious 7-day backpacking route with 50,000 vertical feet of gain & loss.

Extra body weight adversely affects athletic performance. This crew had little, and thus were able finish a super ambitious 7-day backpacking route with 50,000 vertical feet of gain & loss.

Body weight. I’m as lean as I’ve been in years, but I could still lose additional body fat before I risk recovery speed or my general health. (At least I think so — Amanda and my mother would like me to start eating more ice cream). Excess body fat has a significant effect on running performance, especially on mountainous courses. In fact, I attribute most of the drops I’ve seen recently in my running splits on my regular running routes (e.g. 2 minutes on a 30-minute leg with 1,000 vertical feet of gain) to weight loss, not necessarily improved fitness. As everyone knows, the most effective and sustainable approach to losing weight is exercising more and eating less (and better).

Secondary training

If not dialed in, there are other factors that could ruin race day. But they take less time to work out:

Nutrition. I can run for 2-2.5 hours without food or water without noticing a dropoff in performance. But for an 8-hour effort, I’ll need to replenish. The consensus calorie target is about 250 calories per hour, depending on body weight and output intensity. Fluid needs are more dependent on the temperature, sun exposure, and humidity; 20 oz per hour has worked well on recent training runs. I’ve been using Clif products — Shot Energy Gels, Shot Bloks, and Shot Electrolyte Hydration — since the aid stations will have them and since they seem to treat my system nicely.

Supplements. To maintain a proper balance of fluids and electrolytes, I take one SaltStick Electrolyte Salt Capsules every hour. Without them, my body won’t efficiently use the fluids that I’m taking in; instead, they slosh around in my belly, and eventually I can become hyponatremic. For later in the race when I start running low on gas, I also have some 100 mg caffeine pills on hand, too.

Clothing, footwear, and gear. I’ll cover this in another post.

Personal care. Blisters, bloody nipples, and chafing in the nether region get old over 50 miles. I’ve tested my clothing and footwear on training runs to ensure I avoid these problems, and found an easy fix for my nipples — athletic tape.

The taper. I love to run, and after weeks of huge volume I’ll be disappointed to dial it back in the two weeks before race day. But I must in order to race well: by that point, “the hay is in the barn” and there really is no benefit to additional training. To the contrary, I’ll race much better if my legs are fully recovered and rested. Many ultra runners have ruined or compromised their race day performance by failing to taper.

Posted in on October 22, 2014


  1. Gabe Joyes on October 22, 2014 at 12:09 pm

    Just a comment about your volume: 103 miles in 7 days is certainly a lot, and I wouldn’t worry too much about not running over 26 miles too many times. With your outstanding base and experience, going the extra miles during the race will come easy for you.

    One new training approach that worked well for me this year was that I actually ran less days, but more “big” and high quality days. The idea here was to give me plenty of time to rest while still getting miles and the speed I was looking for. For example, at the beginning of a week maybe a 35-40 mile elevation intensive run at a slower pace, followed by a recovery day, a faster 20 mile day, rest, flat fast 15 miles, rest, elevation intensive 15 miles, rest. That gets you 85-90 really high quality miles with a relatively low chance of burn out or hurting yourself. Plus, it trains you to run fast when your legs are exhausted. You could bike or do some core work on all of those recovery days. I’m no pro either, but this helped me make some big gains in my ultra running this year.

    • Andrew Skurka on October 22, 2014 at 12:29 pm

      This is exactly the approach that I’m transitioning into. In the last month, I’ve worked up my weekly mileage to about as much as I can do without getting hurt (probably — unfortunately only one way to find out). From here, the only way I can continue to increase my long run distances is by decreasing recovery day distances. So instead of 26, 10, 11, 26, 13, etc. it’ll have to look more like 35, 4, 5, 7, 40, 3, etc.

      I’m not sure I agree that I shouldn’t put in too many more 25-mile days or more. If I can do 26 with 4k total vertical at 7:40 pace (last week, twice), I can certainly finish 50. But I can race 50? In order to do that, I think I need to put in at least a few long runs that are about that far.

      • Gabe Joyes on October 22, 2014 at 1:18 pm

        Cool, good plan. The only reason I say don’t stress about getting too much over 26 is that I’ve been hearing from a lot of other ultra runners that they are training only up to 30-35 miles on really technical, elevation intensive terrain as a longest runs before racing 100 miles. I tried that out this year, and I was admittedly nervous about it, but it paid off. I did a Zion Traverse in June, a bunch of 30-35 mile runs in the Winds all July and August and raced The Bear 100 in September. I was pleased with my improvement, and I did race hard to the end (I was shocked my last couple miles were at an 8:00 pace). Of course, this strategy doesn’t work for everyone, and I can understand your hesitations especially after being out of the racing scene for awhile. You’ll do what feels right and I am sure you will have a great race in December. Good luck!

  2. Jorge on October 22, 2014 at 3:00 pm

    If I were in your shoes, I would trade distance for specificity. I have run 100 miles/week a couple of times but only when training for 100 milers.

    I have never run 50 miles in one seating, so to speak, when training for a 50 miler or 100 miles when training for a 100 miler. In the case of the 50 miler, my peak week-end is 32 miles on Saturday, steep, followed by 25 on Sunday, flatter. On a course that mimics the biggest features of the target race – e.g., the biggest climb/descent and the “pointiest” – biggest slope up and down. The back-to-back gives me the mileage I need while giving my body the ability to build up comfortably; I will still feel the fatigue from the previous day’s workout on Sunday so that I have the psychological experience of how I will feel late in the race.

    I find some strength training is helpful to get quads and hamstrings ready for technical climbs and descents at high speed. One or two days a week, 30 minutes.

    I also use periodization – increasing volume and intensity in waves of 3 or 4 weeks – each wave starts higher than the previous wave’s starting point and lower than its ending point. This opens lots of time for my body to rebuild after each effort (you will need less time because you are 1000 years younger – but still).

    Each week, I include a speed workout and a hills workout – I will need these capabilities or “specialized gears” at specific points in the race.

    Your nutrition and hydration plan looks fine – make sure to test it and adjust it during your long runs. Consider some solid food, perhaps relying on the aid stations. A 50 miler is at the edge of my tolerance for gels only – but each person is different.

    All of this works for an aging runner who wins age group but is at best 10% deep into the pack, so it may be completely irrelevant to real athletes like you! 🙂

    Good luck! NFEC SF is a wonderful course!

  3. Joe on October 22, 2014 at 5:46 pm

    Given that you don’t have much training time, this may be advice best taken for the next race after this one coming up.

    I would take a look at some of the books by Jeff Galloway and the folks at Furman University (book called ‘Run Less Run Faster’)

    And you’re right on the injury part. Galloway says that the principle factor in determining whether progress will be made is whether you can remain injury-free.

  4. Greg on October 23, 2014 at 6:58 am

    Out of curiosity, after having so much success in such a short-lived ultra career, why not race more? (Or is this 50-miler a reentry to racing?)

    With your Leadville finish in ’08 and your deep distance hiking background I’d imagine a race like Hardrock 100 to be in your wheelhouse.

    • Andrew Skurka on October 23, 2014 at 8:24 am

      Great question with a fairly straightforward answer.

      My Alaska trip was a pivot point. In the years prior, I was “living the dream” by backpacking and running as much as I wanted to. But that lifestyle has an expiration date, or at least it did for me. In particular, I got tired of having so little geographic and financial stability — living out of tubs, renting month to month, and often not knowing when or how I would get another paycheck. In the years since the Alaska trip, I sacrificed the dream for an existence with more certainty. I own a home and have several proven and reliable income channels. It’s about time to pivot again: I can now live the dream, but from a position of certainty.

      So, back to running. The main reason I haven’t entered any ultras in 4 years is simply a matter of time. I’ve been preoccupied with guiding trips, speaking, and writing; I also got married last summer. Even if I was available on race day, I was unable to allocate adequate time for training. And I wasn’t interested in running ultras for which I was half-trained. Like TNF, I want to toe the line and be ready to compete. I won’t be fully trained for TNF either, but I’ll certainly be in better shape than I have been since 2010.

      A secondary issue has been the lottery system that many top ultras use to finalize the field, e.g. Hardrock, Western, and now even Leadville. I wasn’t willing to train and race a B-level ultra for just a chance of getting into a big dance. TNF is really appealing in this respect: I wanted to race it, so I registered, and I’m in.

  5. Albert on October 23, 2014 at 3:07 pm

    Having been a beneficiary of your pivot by participating on a number of your client trips, I totally understand the lifestyle change – the focus on new ambitions, marriage, mortgage, etc. But I’m really excited to see you do something like this and hope you do more going forward. In many ways I miss the pre-2010 Skurka – the big challenges and adventures, pushing the boundaries of further, faster, lighter plus the many goofy and not-so goofy videos posted to youtube.

    I, along with many fans and friends, would love to see you do another audacious adventure…from a position of certainty of course :-).

    Best of luck in the race!

    • Andrew Skurka on October 23, 2014 at 3:27 pm

      I think you’re going to a big increase in these types of efforts starting in 2015. (I feel like I’ve been saying that for a few years now, but I really, really mean it this time.) I miss the pre-2011 Skurka, too.

  6. Elizabeth on October 30, 2014 at 10:44 am

    Hope your training is still going well and you are injury free, good luck in Marin. Looking forward to your post on clothing, footwear and gear.

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