Ultramarathon Training Volume

Training volume is the ultrarunner’s top concern. Without a solid endurance foundation those 50-mile, 100k, and 100+ mile races will be extremely difficult to complete. However, overdoing the miles can quickly lead to our undoing in the form of injury, chronic fatigue, and poor performance. The goal is to develop an approach that will challenge you, but create only positive training benefits.

Volume Is Good

It’s true! Increasing weekly mileage brings increased performance. If we do nothing else but simply add to the time we spend on our feet each week, several beneficial physiological adaptations begin to occur due to this new accumulated volume.

  • The body will become proficient at burning fat, its optimal fuel source.
  • Muscle and liver glycogen, the major forms of stored carbohydrates in the body, will be more effectively amassed and utilized.
  • The size and number of muscle capillaries and mtochondria, the blood vessels and cellular factories that facilitate aerobic energy, will increase.

We’ll tangibly experience these internal gains in these ways:

  • What once were long runs become shorter runs.
  • Faster recovery after running up steep hills.
  • Desire to race farther.
  • For those new to the volume increase, personal records in ultra distances.

This is great stuff! We’re seeing improvement, our confidence is high, and we’re doing things we never thought possible. Yet it is here that our unbridled enthusiasm may lead us into trouble if we continue to add mileage without an appropriate plan.

Adding Mileage Sensibly

Keep yourself in check and increase your mileage successfully by following these guidelines:

  1. Increase your weekly volume by 10–15% for two to three weeks, take a recovery week, then increase 10–15% again for two to three weeks, and repeat. For example, an injury-free runner that has been averaging 50 miles per week or 8 hours per week for a month might do this:


Mileage or Time/Week (in hrs. and mins.)


55–58 or 8:45–9:15

4 (recovery week)

50 or 8:00


60–67 or 9:30–10:45

8 (recovery week)

55 or 8:45


  1. Increase the length of the runs that you already have scheduled before adding more runs to the week. An hour run is aerobically more beneficial than two 30-minute runs. However, see this article on two-a-days if your schedule or injury rate makes this scenario impossible.
  2. If you’re inexperienced with this newly added volume, avoid racing and high intensity workouts while you ramp up. Keep your efforts and paces primarily within the endurance-based training zones. Temporarily crossing into stamina-based training zones is okay and sometimes unavoidable on hills and during the final few miles of your longer runs, but be sure to recover well and take it easy on the following days’ workouts.
  3. Run on soft surfaces.
  4. Do not run in worn out shoes.
  5. Once or twice a year schedule three to four weeks of low-to-no mileage or just cross train.
  6. If you’re injury prone or enjoy cross training use the elliptical, cycling, cross-country skiing, or another aerobically challenging sport to build your endurance capacity in place of a running workout.
  7. Remember that volume can be measured in time or distance. If you spend the majority of your time on rough terrain it can be relatively slow-going, so running for time alleviates the pressure of having to cover a predetermined distance.
  8. Implement and maintain a simple but running-specific core routine. Here are a few exercises you can try at home.
  9. Keep a training log. Keep track of weekly volume, workouts, and how you felt during each of them.
  10. Keep the mileage of your longest runs in line with your goal race distance, but within realistic parameters. Adjust the length of the long run to gel appropriately with your most recent (roughly the last ten weeks) training load. This iRunFar piece on Endurance-Based Workouts will provide you the basic information on the different types of long runs. For back-to-back long runs, cut 25–50% off the first day’s mileage or time in order to determine the length of your second day’s run. For example, if you run 4 hours on Saturday return on Sunday with 2 to 3 hours. Because back-to-backs are time-consuming and tough on the body and mind, schedule them every two to three weeks. Experiment with their lengths and occasionally challenge yourself by including fast finish long runs on one of the two days. Here’s a chart that details optimal long run distances relative to popular ultra race lengths.




Road 50k

16–26 miles (on the roads)

Not necessary

Trail 50k

3– 4 hours (on the trails)

Not necessary

Road 50M/100k

20–30 miles (on the roads)


Trail 50M/100k

4–5 hours (on the trails)


Trail 100M

5–6 hours (on the trails)



  1. You can utilize shorter distance events to help you prepare for your goal race. I’ll discuss this training technique in my next iRunFar column, Racing Yourself into Shape.

Reaching the Ceiling

Though the human body is well designed for running, it wasn’t built to run all the time. Even if you’ve been smart and patient with your volume buildup, there will come a point at which you can add no more. Once you go beyond 60–70 miles per week or eight-to-ten hours per week, depending on your age, genetics, and past running experience, you begin to walk a fine line between what is beneficial and what is harmful. You are your best barometer. Here are some signs and symptoms to watch for that indicate you’ve neared or surpassed your personal training volume ceiling:

  • Injury – Knee, hip, foot, back, or bone issues appear more regularly after you reach a certain volume.
  • Decrease in performance – Finishing significantly slower than recent race times or others you normally compete with finish far ahead of you.
  • Consistent soreness or fatigue – Running should be invigorating.
  • Lack of motivation – You should look forward to your runs, not be looking for excuses to skip them.
  • Significant weight loss or gain and sleep disturbances – Overtraining can disrupt cortisol (a hormone released by the adrenaline glands in response to stress) levels that may cause rapid shifts in weight and changes in our sleeping patterns.
  • Increased resting heart rate – Higher than normal resting heart rates (best when taken upon waking in the morning) can indicate dehydration, the need for rest, or impending illness.
  • Unable to honor work and family commitments – For 99.9% of us running isn’t a means of subsistence. Don’t ignore your responsibilities in favor of more time on the trails or recovering from that added time. We’re doing this for fun!

In the mildest of cases, a few days or weeks away from running will help you get back on track. However, in severe cases, it may take months or years before a runner can returns to the sport. If you catch these symptoms early enough, take a recovery week or two. By cutting your volume by 50% for 7–10 days you’ll lose no fitness but will reap the benefits of restored energy and health. Other healing protocols can be found in my recovery article. Use this time not spent running to focus on your nutrition, sleep, family, and friends.

The Next Level

What happens once you’ve reached your volume ceiling? Are you done? The answer is: Absolutely not!
Up to this point you’ve only been increasing your volume though endurance-based workouts. You can now experiment with other types of training. Start by introducing hill workouts, stamina-based steady state runs, and improve on your form and running efficiency with strides and drills. In a month or two you’ll be stronger and able to challenge yourself with tougher tempo runs and speed-based workouts. Because we can’t all run 100+ mile weeks we must make the miles that we do cover count.


Pfitzinger, Pete. Essential Ingredients II, Runner’s World & Running Times. Running Times, 4 Apr. 2006.Torrence, Ian. “The Dream Season.” TrailRunner Apr. 2013: 40-49.

There are 10 comments

  1. Anonymous

    Thanks, Ian, hardly a week goes by when someone doesn't tell me how wrong I'm doing things, I usually don't say too much in my defense, but now I'll just point them in the direction of this article and let it speak for me…

    JV in SD

  2. Alex

    Consistent volume yields consistent results, in my experience. Not that quality sessions and the long run aren't important, but I think they can be overvalued a bit. A certain stimulus is achieved with a certain amount of work, after all, so why go too far beyond that? That is to say, 20X400 is not 5 times better than 4X400, nor is a 50 mile long run twice as good as a 25. Perhaps, those shorter sessions are as good, and perhaps even better, when you consider the relative ease with which you could recover from them. Put another way: I consider myself more fit when I can run 7-10 miles ever day, than when I can nail any specific workout.

  3. Eric S

    Hi Ian,

    Another very informative and timely article — thanks so much! A quick question if you have a chance: currently training to just finish my first trail 50k — according to my schedule, I'll get in 4-5 runs that are between ~3-4 hours, but of those runs, the longest run mileage wise will be 22 miles. Your optimal range is 16-26 for road; 3-4 hours for trail — do you think this is sufficient to just safely (no injury) finish the race? If I tried to do a 24-26 miler it would take me closer to 5 hours and this seems like it'd be too much strain prior to race day.


  4. OOJ

    Another great resource, Ian, thanks!

    I just purchased my first heart rate monitor; that gives some insightful information, as well, on training volume and tolerance.

    My brief experience has been, when my volume is high and I'm overly fatigued, my heart rate will be consistently higher at the same pace/distance; OR, my heart rate will climb and climb at the end of a long run, despite significantly controlling/slowing pace. Both are indicators that it's time to:

    – rest: to finish for the day, or to not add any further mileage to the day/week

    – NOT increased intensity

    – take a recovery day or week.

    Thanks again!


  5. KenZ

    Thanks for another great article. One side comment: increased resting heart rate. This is an OK way to track overtraining… usually. However, endurance athletes can sometimes fall victim to parasympathetic overtraining, in which case your heart rate can be the same or even lower. AND, standard heart rate increases in the morning can lag overtraining/sickness by a few days sometimes. Heart rate variability is a better and more reliable method, albeit really rather biohacking/data intensive, for determining overtraining. If anyone is interested, I can point you towards a few options for tracking.

  6. Alec Martin

    Hi Ian, My friend and I are training for a 50k run. I work a 8am-5pm job Monday through Thursday however. I have about 8-9 weeks of training before we race. I am very new to ultra running too, The most experience I’ve had is 4 years of high school xc and track. I have made a rough training schedule consisting of one-run days, with a tempo on Wednesday, possibly strides on Thursday, and longer mileage on Friday through Sunday. Like I said, I am very new to this type of running, and would really appreciate if you could respond with some pointers and tips, in terms of preparation for my race. Thanks!

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