80/20 Running Review

(If you’re looking for other training plans and more running books, check out my reviews of Hansons Half Marathon Method and Run Less, Run Faster!)

Matt Fitzgerald is one of the most prolific current authors of running books, with a special focus on sports psychology and nutrition for runners. His many books include Racing Weight, Run: The Mind-Body Method of Running by Feel, Diet Cults, and The New Rules of Marathon and Half Marathon Nutrition. In 80/20 Running: Run Stronger and Race Faster By Training Slower, he shifts away from a close focus on training your mind and eating right to discuss the training according to a high-volume, polarized intensity principle. Essentially, Fitzgerald argues that in order to race faster, you have to run slower.

Yes, running slower will make you faster. More specifically, running slower about 80% of the time will make you faster. The other 20% of your running will be done at moderate to high intensities (tempo pace or faster). The cut-off for low-intensity is when you reach ventilatory threshold, which is slightly below your lactate threshold (tempo pace). Your ventilatory threshold is when your breathing suddenly become more rapid; for a 50-minute 10K runner (approx. 8:00 per mile), this threshold is at about 8:40/mile pace. When running at or below 8:40/mile paces, a 50-minute 10K runner is training at a low intensity.

Essentially, Fitzgerald is urging runners to slow down. Most runners train too fast, which can lead to overtraining, injury, and stalled progress. When you go too fast on your easy days, you can’t push yourself as fast on your hard days. Running too fast during most of your runs also prevents proper recovery from happening.

 80/20 Running Review

Why the 80/20 ratio? Fitzgerald derives these numbers from the research of Stephen Seiler and the training methods of Arthur Lydiard (who famously popularized the long slow distance run). Runners who only spend 20% of their training at high intensities, which includes many elites, will see maximum results on race day compared to those who run at 65/35 or 50/50 ratios of low intensity to high intensity. Arguably, training at an 80/20 ratio is what has made Kenyan and east African runners the top marathoners in the world, and only as more U.S. athletes adopted this method of training did they begin to reclaim spots on the podium.

Running a majority of your miles at a low intensity allows you to run more miles overall. By running higher mileage, you are able to continually build your aerobic capacity. However, in order to truly maximize your aerobic capacity, you need to include some high-intensity workouts. With high-intensity training, the emphasis is on quality over quantity. You shouldn’t use your harder runs to squeeze extra mileage into your week, and you should not pile on extra intense workouts as you prepare for a goal race. Fitzgerald cites a 1999 study by Veronique Billat that found athletes who did three high-intensity workouts per week actually saw a decrease in their VO2max and, correspondingly, slower race times. 

The most interesting section of 80/20 Running is Fitzgerald’s discussion of the impact of a high volume of low-intensity training on fatigue resistance. Fatigue resistance is both physical and mental, and is essential to successful racing. By running more at a lower intensity, you teach your body and mind to push through prolonged efforts and get comfortable with the discomfort of running. Fitzgerald states, “The slow-burn type of suffering that runners experience in longer, less intense workouts is more specific to racing. Speed-based training teaches the mind to expect a quick end of the discomfort of running in a fatigued state…In contrast, low-intensity, high-volume training teaches the mind to accept that it might as well make peace with it’s suffering because it won’t end anytime soon” (76). By running for longer times at lower intensities, you actually strengthen areas of your brain, including your insular and temporal lobes, and thus change the way your brain perceives effort and discomfort.


Fitzgerald offers three methods for monitoring and controlling intensity: perceived exertion, heart rate, and pace. He creates five zones with corresponding heart rates, perceived efforts, and paces, with the McMillan Calculator serving as the guide for determining pace.

80/20 Running contains 12 training plans: 5K, 10K, half marathon, and marathon each with a level 1, level 2, and level 3 plan. These training plans use workouts described in earlier chapters of the book: low-intensity runs, moderate-intensity runs, and high-intensity runs. Low-intensity runs are recovery runs, foundation runs (easy runs), and long runs, and are all done in zones 1-2. Moderate-intensity runs include tempo runs, fast finish runs, cruise intervals, and long runs with fast finishes or speed play (zone 3). The high-intensity run category covers speed play runs, hill repetitions, short intervals, long intervals, and mixed intervals (zones 4-5); all of these are run for time rather than distance (so 2 minute repeats instead of 400m repeats).

The plans all include 6-7 days of running, with a few weekly two-a-day runs in the level 3 plans. Every third week is a cutback week with one of the easy/recovery runs removed and less mileage overall. Even though you are doing a lot of easy running, these are not easy plans. Here is a sample week from the Level Two Half Marathon plan:
Monday: 45 minute easy run
Tuesday: 48 minute run with 28 minutes at tempo pace

Wednesday: 45 minute recovery run
Thursday: 45 minute easy run

Friday: 40 minute run with 3 x 5 minutes at zone 4

Saturday: 45 minute easy run

Sunday: 12 mile long run with 10 ¼-mile surges at tempo pace

 The plans also offer cross-training alternatives on some of the easy/recovery run days. The cross-training options are all physiologically similar to running and include pool running, the outdoor elliptical bike, the indoor elliptical, cycling, uphill treadmill running, slideboarding, and anti-gravity (Alter-G) treadmill running.


Even if you don’t use the plans in 80/20 Running, the principles of hard/easy training and the tips on the mental side of brain training make it a useful read for any runner who is trying to run a PR or simply enjoy their next race more.


(Disclaimer: This post contains Amazon Affiliate Links. I purchased this book on my own and am not affiliated with the author or publisher, and all opinions are my own. I just love books!) 

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4 Responses

  1. I would say that I follow this type of rule–most of my running and such is at a moderate intensity. I definitely trained too fast for the majority of my runs during the first marathon, and I ended up with ITB issues. Still finding the balance, but I think that this is what works for me!

    1. I hear you on training too fast for first races! I did that when I decided to run what could have been my first half marathon…and that was when I got my injury. Whomp whomp. Yay for finding the balance of what works for you – it always seems like an on-going process but finding what works is an awesome place to be!

  2. You gave a good review of the content, but I wonder if you tried the method and had any results. If so do your results backup the claims?

    I’ve read the Run Less, Run Faster book and the two seem to NOT be complimentary (but that is w/ me not having read 80/20 yet). Does one plan make more sense to you?

    1. The Run Less Run Faster is definitely a different training philosophy than 80/20 Running, as 80/20 Running relies heavily on easy runs, while Run Less Run Faster does not have you do any easy runs (but rather cross-training). While I don’t follow 80/20, I do follow the Hansons plan (which is reviewed on the blog as well) that practices a very similar philosophy: lots of miles, most of them very easy, and a few workouts where you push yourself hard. So far, I’ve had very good luck with that type of training. Hope this helps! 🙂

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