18, 20, or 22 Miles: Pick Your Poison

The other day I wrote a post about how you can finish a marathon with your longest run being 20 miles.  However, many training plans call for something different and I felt it was important to briefly discuss these various distances.  Some training plans call for as little as 18 miles for your longest run while others call for 22-23 miles.  Below is a breakdown of these different runs and why they might or might not work for you.

The 18 mile long run:  The biggest and most popular proponent of the “less is more” theory is the Hanson brother’s team who work with many successful elite runners.  Some of their plans might even only go up to 16 miles.  One of their main reasons for this approach is that a 20 mile run could add up to 40-50% of an athlete’s weekly mileage and this isn’t necessary and perhaps too much for your body.  They follow the belief that instead of looking at an 18 mile run as eight miles short of a marathon, it is better to consider them to be more like the last 18 miles you would experience during the race.


Many coaches prefer this method because they feel 20-22 miles during a training session is far too much mileage and can lead to injury.  This might be a more beneficial approach for a beginner or a runner who tends to get injured with higher mileage.  However, as the Hanson’s have clearly proven, this method works incredibly well for top elites as well.

The 20 mile long run:  From my experience this is the most common long run you will find on a traditional training plan.  As I noted in my previous post, this distance will properly prepare you for race day while avoiding too much mileage and lead to injury.


I personally think this is an ideal long run distance and prescribe this for almost all of my runners.  Some prefer to have two 20 milers in their plan and although I don’t feel this is necessary, it can certainly help you feel both physically and mentally more prepared.  In my opinion this is a distance that is achievable for beginner through advanced runners.  It is just far enough to make you question your sanity, but not so far that you risk pushing your body too far.

The 22 mile long run:  To be honest, I am a huge fan of having one of these on my own personal training plans.  I like to have a 20 miler a few weeks before this epic run.  I do however, think this is best to be used for athletes who have comfortably built up to 40-60 mile weeks before beginning training and do not seem to have injury issues associated with higher mileage.


While I prescribe this in some training plans, I tend to reserve this for more advanced/experienced marathoners and athletes looking to set PR’s.  If you are looking to simply finish your first marathon or enjoy running several marathons per year for the sake of running them, this would definitely be an overkill.

Pick your poison:  There are so many ways to approach training for any race.  As you can clearly see from the above information, there are many different ways to train for a marathon and achieve success.  I believe it is important to determine what your individual goals and physical capabilities are.  Remember that the hardest part of marathon training is more often than not, avoiding injury.  With keeping that in mind, it is essential that you never over extend yourself.  A properly laid out and periodized plan will help get you to the race, regardless of which long run you choose.

What is your preferred longest run during training?

27 thoughts on “18, 20, or 22 Miles: Pick Your Poison

  1. I haven’t trained for a marathon yet, but I am slowly making my peace that I will and probably I will start very soon. I am curious what will I pick… Certainly going to keep your tips in mind!

  2. My longest training run was 18 miles, and that was for my first marathon ever. Since then, and I am about to run my 21st in Chicago, my longest has been 15. Pounding out the miles during training pounds me right into the pavement, tiring me out and causes a lot of aches and pains. I am in my mid 40’s, and just feel it is unnecessary these days. For Chicago, my longest two were both 13.1 races a week apart. At this point I know I can conquer the marathon, so I don’t beat up my body during training.

  3. Nice overview of the long runs…I’m just finishing my 5th marathon cycle ahead of Chicago and for this plan I went with a 20 and a 22. The 20 I wanted to simulate race pace and conditions and it went great, exactly as planned. This past weekend was the 22 and I really had to grind it out, not sure if I will do that again. Will see how it goes in Chicago I guess, hoping to PR and break 4 hours. Next year training will be different as I change up to 4 marathons in my quest to eventually run a full in every state!

  4. I’m with you on the 22 miler, but my thought process is a little different than what you mentioned here. I once read an article that mentioned that running over the three hour mark will actually give you “diminished” returns – meaning for multiple runs over 3 hours duration the law of diminishing returns kicks in as far as any cardiovascular improvement is concerned. The mental benefit of knowing one can handle the distance must be weighed against the down-time required to recover.

    • This is a great point. Some people argue that recreational or slower runners shouldn’t do 20 because it goes over that three hour mark. The tricky part is that these are often the athletes who need to train to get their bodies there or to mentally know they can get there. It is a tough balance.

  5. Ahh, hit send too soon. Sorry if that came off sounding a little weird – what I meant to say but didn’t get to edit is that I think there is a huge mental benefit to running long – 20+ miles – for any runner, regardless of pace. I just think that if it takes the runner more than 3+ hours to run the distance (basically anyone running a 9 min mile or slower – not a bad thing, just a fact) that they should limit the number of 20+ mile runs and stick to those under the three hour mark. I think they should absolutely be done and in a training plan either way, I just think the number of them should be based on the pace of the runner. If that makes sense!!! Sorry so wordy! I wish we could go back and edit responses!

    • Makes absolute sense and I’m glad you added this. After I hit reply I realized that I wanted to add that for someone who is going to do a six hour marathon they might even need to get that 20 in that goes over three. Three more hours is a lot to add on! It’s definitely a hard one to balance between what is enough and then too much.

      • It’s always such a balancing act…and it’s so different for every person! I think you are such a great coach because you are so in tune to that. The coach I was working with would do what worked for him when he trained me, and it wasn’t a good fit. I love how you see the benefit to different schools of thought. Your runners are lucky to have you!

  6. I love the 20-miler. I usually incorporate 2 or 3 a training cycle, instead of adding longer milage. I think that most of training is mental, so if you can safely run those higher distances or high milage frequently, I’m all for it. Great post 🙂

  7. I agree with the hardest part o marathon training being making it to the end without injury. Being able to run a 20 miler has always been easier for me than having to sit out of training because I built up my mileage too quickly.
    I like the 3-hour rule personally, not just because of preventing fatigue that could lead to injury, by also because I don’t have more than three hours on a given day (four if you include dragging from the kitchen to the bathroom and some downtime)!
    I’m looking to try two 20-milers in a cycle for the first time. But first, I’m building super slowly into the 40-45 mpweek 🙂
    Thanks for the overview!

    • I think that mileage build up will be super beneficial for you. And now that I have a baby I wonder how I will even have two let alone three hours for a long run. It definitely is time consuming!

  8. so well-timed for me, as this has been on my mind the last few weeks as i finally started getting into my marathon training groove and realized i had to buck up for some long runs. the last time i ran a full, my longest run was 20 miles; this time, i decided i wanted at least 21 under my belt, so i could say i did over 20. i felt good enough to run 23, and i feel SO much more prepared going into these 2 weeks before the race now!

  9. Hi. Interesting post and it’s a predicament that I’m in right now. I ran a 20 miler last weekend and due to time constraints and fatigue, I can’t go any higher. So I’m tapering for the Dublin marathon on October 26th. Quick question. Do you think that I should be higher considering I have another 6 miles to go? Does that affect many people mentally?

    • This is a great question and interestingly enough I did a post the week before this on how it is proven that 20 miles is plenty enough to get you to the finish. In fact, some elites only do 18. Your body is ready and now you need to rest it. Scour through and find that post if you want some more reassurance. Best of luck in Dublin. If you made it to 20, I am certain you will get to 26.2!

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