Your Ultra-Training Bag of Tricks: Two-A-Days

I was first introduced to two-a-days (also known as doubles) in high school, though I wasn’t the one doing them – our top runner was. He hadn’t trained enough over the summer and this was our coach’s method of getting him in shape quickly before the crucial end of season races. In just three months, the team witnessed his transformation from an out-of-shape couch potato to one of the top runners in the state. At that point in my running career, I couldn’t fathom the notion of running twice in one day, however, this certainly showed me that it could work wonders under the right circumstance.

Two-a-days refers to completing two workouts in the same day. One of the two runs is usually shorter and easier in effort.

There are two purposes to two-a-days:

  1. Recovery – A short session of “jogging” several hours following a tough stamina-based or speed-based workout is a form of active recovery. It helps flush the wastes accumulated in the legs and can be used to warm the body before a foam roller or stretching session.
  2. Endurance improvement – The day’s additional run acts as an endurance-based workout by training the body to become efficient at burning fat and storing muscle glycogen, increasing the size and number of muscle capillaries and mitochondria, and teaching the body and mind to keep going when fatigued.

Who should be doing two-a-days?

  1. Established high mileage ultrarunners who consistently run more than 75 miles or 10 to 12 hours a week.
  2. Those who are physically prepared to increase their weekly volume. Runners who have steadily improved their fitness through single day workouts, but have reached a performance plateau.
  3. Runners with limited days of the week or short windows of opportunity to train, such as firefighters and individuals in the medical field.

Who should avoid two-a-days?

  1. Runners who have a history of or currently battle injury should avoid running twice a day. Athletes who succumb to injury easily but are looking to improve on their endurance with the use of a second daily workout should invest their time safely with non-impact aerobic activities like cycling, elliptical trainers, swimming, and Alter-G treadmills.


  1. Those who’ve never run twice per day should start with one or two second runs during the week and, if all goes well, slowly build to three or four per week in as many months.
  2. Second runs can be done morning, afternoon, or evening, but timed so that ample recovery can occur before or after the primary workout. When first starting out, avoid performing second runs on days that are recovery focused.
  3. The distance of the second session can vary greatly. Twenty minutes is enough to get the blood flowing and warm the muscles, while 60 minutes is plenty in order to build endurance. Again, ensure that the distance of these second runs doesn’t impact the following day’s workout.
  4. Whether your ultra takes you to the road, trail, mountains or beach, you should keep these second runs as simple as possible. Avoid adverse weather conditions and run at an easy pace on soft, flat surfaces.

Two-a-day workouts are a relatively safe way to increase your mileage, improve your fitness, and work around a busy schedule. As an extreme example, in 1994, while working full time, David Horton was able to fit in three workouts a day to prepare his body and mind for the Trans-American Footrace: a ~3,500 mile coast-to-coast event. Horton explains, “I was running three times a day during the week; in the morning, some at noon, and then some after work. I averaged 180 miles per week for two months, with the biggest training week being 193 miles. This training readied me for the Trans-Am, even though during the race we averaged 315 miles per week. That was 45 miles per day for 9 weeks at 9:15 per mile.”

Call for Comments (from Bryon)
Have you ever used two-a-days in your training? Do you think they benefited your fitness?

There are 18 comments

  1. Darthrunner

    I'll often do doubles simply because my schedule doesn't allow one longer run in a day. A few times I have done a "triple" (run to work, at lunch and home from work) as a substitute for my long run. I try to run each at about 80% effort. The next day I feel fairly worked. Any thoughts or input on the triple as a sub for long runs?

    1. Ian Torrence


      Splitting a three hour run into three separate runs will never yield the same training effect. Because of the recovery you're allowing by doing a triple you miss out on the many phycological and physiological benefits of the long run. For example, it's impossible to dial in a nutrition regime with 3 one-hour runs in lieu of a single three-hour run.

      However, like in David Horton's example above, he was able to use triples during his full-time work week to amass the miles. Keep in mind that he was also running, and I quote, "…a long run of 40 to 50 miles on the weekend."

      So use the triples to add mileage to the legs, but keep the long run in your plan to induce full endurance-based training benefits.



  2. art

    my body loves two a days, but usually in the reverse order mentioned.

    at my age, I need a lot of warm up before pushing it. morning run one hour easy. aternoon run 1-2 hours medium or hard depending on mood. morning run acts as a great warmup, much of which carries into the afternoon.

  3. panos from greece

    I do doubles in my preparation period before i start my main training plan (before base period). I usualy do 1h-1h30m easy runs @70-80% maxhr with running technique drills and easy plyometrics.

    I have found that this type of training before my main plan begins helps me to:

    – improve running technique

    – improve running economy

    – improve body composition by burnin much fat

    – regenerate my aerobic capabilities

    – prepares my body fast to accept the training load following

  4. Brian

    I'm just Joe Average but I've done doubles since I got back into running 3 years due to the demands of work and home. I do an easy paced morning run and typically a harder treadmill workout at lunch. It's the only way I can have a 2 hr daily commute, be a dad to 3 small kids, and run 80-90 miles per week.

  5. Harry Landers

    My schedule has me doing most of my running in the early morning, but I find that it makes sense to add an afternoon double or two each week, as I'm preparing for a spring race. I know that I may need to be prepared to run in spring heat and the cool mornings just don't give me any acclimatization. Adding some warm afternoon/early evening runs gives me an opportunity to prepare myself, while letting me bump up my mileage, as well.

  6. Matt

    I've always used two-a-days on days that I do hard workouts, either in the afternoon to recover from a morning session or in the morning to warm up the body and mind for the afternoon session. I always seem to run those afternoon sessions better.

  7. Alan

    Great info, as a firefighter who works a 24 on 48 off schedule it's often hard to be consistent. I've often thought of incorporating doubles into my workouts and look forward to reading some more on it. I've got the ability most days to train at work but try to refrain from redlining it as I may have to jump in full gear at a moments notice and go into a burning house. Generally a miserable experience when you've already put in a few hard miles on the treadmill.

  8. trigirl

    i added 2 runs a day once a week while training for my first 50miler.

    i did a interval session in the am and then in the evening an easy run and i had in my mind that the distance for this double day should be 20k. it worked and felt great.

  9. Rob Y

    Two-a-days have been my bread and butter since I started running ultras over 17 years ago. However I typically only incorporate them when I'm cycling up and building big miles in preparation for 100 mile (or longer) events. The cycles of added stress and fatigue along with recovery really seems to aid in building my endurance and strength by race day. The biggest effect I've seen from doing the two-a-days is that I feel so much stronger during the race and post race recovery is much quicker.

  10. konrad

    Let's hear it for making family time a priority! I commute to work round trip 14.5 miles usually on average about three times a week but often more. After working outside as a groundskeeper in North Carolina heat those runs home can be absolutely brutal but it's an easy way to simulate being really trashed during a race. The best thing about running to work is that when I get home I'm DONE for the day!

  11. Emily

    I'm a die-hard morning runner and my husband is a morning sleeper who's usually just getting up as I'm getting back, so I do doubles a few time a week in order to run with him. Since he usually runs a shorter distance and easier pace than I do in the mornings, it works well as a recovery run.

  12. Digby

    I commute to work daily, alternating my bike and my feet each way. As I build up miles I use the 6 mile journey as a back to back. The morning run normally being faster paced and then a recover run on the return. For double punishment a long run the next day works really well…. but I have learnt to listen to my aging limbs and so will take additonal rest or bike days to prevent any damage; recovery this is key. This worked so well for me in building up to UTMB last year and kept me strong on the hills, will definitely start this programme again… tomorrow!

  13. Jared F

    I used two-a-days once a week last year heading into my first 50 miler. This year I plan to do two-a-days 3 times per week for the sole purpose of fitting in more miles. Some would call these junk miles, but for me I see a direct result of more miles meaning better results in races.

  14. Jared F

    Good job Brian! I too am adding morning runs this year since I don't want to take any more time away from way to cheat on her with that companion we all call "running." I already spend weekend long runs away and a late evening here and there, so adding a few more hours a week I didn't feel would be wise. I start morning runs this week and so far so good!

  15. Laron T

    I started using doubles regularly last summer in training for a marathon but I used doubles in training for a 50-miler this past winter as well.

    I liked to run very easily in the morning, usually, amassing 2-5 miles. Sometimes, I like to run hill repeats in the morning at my base endurance effort as well. I put these runs in about 3-5 days a week.

    Then, in the afternoon, I run my usual training pace runs. Hence, they're a bit faster and a bit longer in general than my morning jogs. I also put in my speed sessions and sprinting, etc. during these afternoon workouts.

    I like using the morning jogs to ease me into waking up for the day. I also have seen improvements in overall fitness and enjoyment in running by putting these morning jogs in. The additional mileage also helps me with weight management. However, I try not to be overzealous about the morning jogs. For example, if I feel like I'm exhausted and need extra sleep, I'll sleep instead of run. Likewise, if I feel the need for speed, I'll make it a fartlek or something of the sort. Finally, I let the way my body feels somewhat dictate the distance I put in but I'd say the average is about 4 miles.

    I have found that doubles are a great way to add mileage as well. It seems like the only way I could ease my way into running 80+ miles/week in training.

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