Ultramarathon Training Volume

Learn why training volume is important for ultramarathoners and how you can find your optimal training volume.

By on April 4, 2023 | Comments

Training volume is the ultrarunner’s top concern. Without a solid endurance foundation, those 50-mile, 100k, and 100-plus-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.

Ultramarathon training volume - Meghan Hicks - Molas

Photo: iRunFar/Bryon Powell

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 mitochondria, 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 see 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.

Ultramarathon training volume - Meghan Hicks - Moab

Photo: iRunFar/Bryon Powell

Adding Mileage Sensibly

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

  1. Increase your weekly volume by 10 to 15% for two to three weeks, take a recovery week, then increase 10 to 15% again for two to three weeks, and repeat. For example, an injury-free runner that has been averaging 50 miles per week, or eight hours per week, for a month might do this:
Week Mileage or Time/Week (in hrs. and mins.)
1–3 55–58 or 8:45–9:15
4 (recovery week) 50 or 8:00
5–7 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 life schedule or injury predisposition makes sticking to single runs 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 ok 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 an 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. Spending most of your time on rough terrain can be relatively slow-going, so running based on time duration alleviates the pressure of having to cover a predetermined distance.
  8. Implement and maintain a simple but running-specific strength routine. Here’s an excellent protocol 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 match appropriately with your most recent (roughly the last 10 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 to 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 four hours on Saturday, return on Sunday with two to three 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.
Race Distance/Time Back-to-Backs
Road 50k 16–26 miles (on the roads) Not necessary
Trail 50k 3– 4 hours (on the trails) Not necessary
Road 50 Miles/100k 20–30 miles (on the roads) Yes
Trail 50 Miles /100k 4–5 hours (on the trails) Yes
Trail 100 Miles 5–6 hours (on the trails) Yes
200 Mile+ Events 5–10+ hours (on the race-specific terrain) Yes & Back-to-Back-to-Backs
x x x
  1. You can utilize shorter distance events to help you prepare for your goal race. I discuss this training technique in my iRunFar article, “Using Races to Prepare for Your Goal Event.”
Ultramarathon training volume - Bryon Powell - Arrastra

Photo: iRunFar/Bryon Powell

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 ultramarathon training volume buildup, there will come the point at which you can add no more. Once you go beyond 60 to 70 miles per week or eight to 10 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 adrenal 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 of overtraining, it may take months or years before a runner can return to the sport. If you catch these symptoms early enough, take a recovery week or two. By cutting your volume by 50% for seven to 10 days, you’ll lose no fitness but will reap the benefits of restored energy and health. Other healing protocols can be found in our recovery article. Use this time not spent running to focus on your nutrition, sleep, family, and friends.

Ultramarathon training volume - meghan hicks - autumn San Juans

Photo: iRunFar/Bryon Powell

The Next Level

What happens once you’ve reached your volume ceiling? Are you done? Absolutely not!

Up to this point, you’ve only been increasing your volume through endurance-based workouts. You can now experiment with other types of training. Start by introducing hill workouts and stamina-based steady-state runs, and improve 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-plus-mile weeks, we must make the miles that we do cover count.

Call for Comments

  • How do you track your volume based on time or distance?
  • Do you have a particular rule of thumb for your weekly running volume?
  • Have you experienced the effects of overtraining?


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

[Editor’s Note: As one of iRunFar’s best training articles, we’ve worked with author Ian Torrence to update this article before resharing it.]

Ultramarathon training volume - Meghan Hicks - Arrastra

Photo: iRunFar/Bryon Powell

Ian Torrence

Ian Torrence has more than 12 years of experience coaching runners of all levels. Ian has completed more than 220 ultramarathons, with 50+ wins, since his first ultra finish at the 1994 JFK 50 Mile. Ian and his wife, Emily, are online coaches at Sundog Running. Information about his coaching services can be found at SundogRunning.com.