Coach Jeff

Written by Coach Jeff


Why is Aerobic Training Important to Runners?

In one of my earlier posts I discussed the difference between aerobic and anaerobic training and the effect each can have on your performance.

While I made some general claims about the importance of running aerobically, I think it is useful to more thoroughly explain why knowing the difference between aerobic and anaerobic running is so important.

Aerobic running always confused me, but this article explains why it is important, and how to know if you are running aerobically. Very helpful!

This chart signifies the percentage of aerobic or anaerobic contribution it takes to compete at certain distances. While this chart exemplifies distances that are rather short for the average person reading this post, the implications are nonetheless profound.

As you can see in this chart, even for a “short” event like the mile, over 80% of the energy required to run the race is produced via aerobic metabolism.

5k and 10k specific training

Take a look at that again.

For an event distance just three miles long, 84% of your running is aerobic!

For the 10k, this number shoots to 90% for males and 95% for females. In the marathon and half marathon, the aerobic contribution is close to 99% for both men and women.

With this staggering number now so blatantly obvious, the importance of understanding aerobic running from anaerobic running can be fully appreciated.

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How do I know if I am running aerobically?

While you’re running, you should be able to hold a short conversation.

It doesn’t need to be Shakespeare, more like a brief chat with a friend.

If you’re by yourself, try telling yourself what you plan to eat for supper and with whom. If you can’t get the words out without gasping for air, you’re running too fast.

Looking for a more detailed plan of action? You can use heart rate training to closely monitor your effort or use these running breathing tips to get you on track.


If you are researching aerobic running, there is a good chance you are interested in training for an upcoming race.

Are we right?

If so, you might be interested in learning more about the following:

Everything You Need to Know about 5k and 10k Training

Comparison of Popular Half Marathon Programs

Half Marathon Specific Training

Comparison of Popular Marathon Programs

Marathon Training Schedule and Guide

Hopefully this helps you on your running journey. You can sign up for our newsletter on this page, and we will keep you up to date with our latest blog posts!


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13 Responses on “Why is Aerobic Training Important to Runners?

  1. I currently run around a 1830 5k, i redshirted cross country season (im in college) and was injured and did NO running last semester. I ran a 17:09 in high school and its frustrating because im so out of shape. How much aerobic base running should i do per week to get me in good standing to start getting faster?

    • That’s a great question, Mark. It’s hard to get too specific without knowing your full training history, but I would look to spend about 2 months focusing on aerobic development. Many college athletes do this over the summer period when they don’t have to worry about racing for the team. If given the opportunity, you would want to slowly build your mileage about 5-10 miles per week from it’s current volume (taking a step back every 4th week) while having one longer run (about 20% your weekly mileage) and one aerobic threshold session (roughly marathon pace). The second month, you could add in traditional tempo runs with the aerobic threshold runs. That would definitely build up the base you need. I hope that helps.

  2. Jeff, great post here. I’ve seen other charts that have a similar theme (this one here is a good one:, but it makes more sense that males and females would have different energy system distributions. My question was where you got this chart. Can you post the original source, I’d love to read the article and maybe get some details on the methodology of how they arrived at those numbers. Thanks!
    -Fran Cusick

    • Hi Fran, unfortunately I wrote this article in 2009/2010 and I can’t remember the source. Pretty poor form on my part not citing it, but I wasn’t quite as saavy back then. If I dig it up, I’ll definitely post here.

  3. I used to run consistent 17-18 minute 5k’s but when it started track season my 3000 was a 10:34 and 1500 a 4:50 now this year my 5k times are high 19’s low 20’s any advice?

  4. Hello, Coach Jeff, I really love your site. I am fascinated/obsessed with the idea of aerobic development. Can you tell me what is meant, exactly, by “in the marathon and half marathon, the aerobic contribution is close to 99% for both men and women.” Does that mean 99% of the race is under the anaerobic threshold? Does it mean that 99% of the race is done NOT in oxygen debt? Does that mean training at marathon pace would be considered aerobic runs? I get this concept confused with aerobic threshold, which, I believe, is about 20 heart rate beats per minute less than anaerobic threshold. I guess my main question is- can you define the difference between “99%” aerobic” versus aerobic threshold (Phil Maffetone, Joe Friel)? Thanks for any information you can provide.

  5. great website Jeff really appreciate the time you have put into this, i have been running on and off for 2 years but the last 6 months or so i have been progressively picking it up. I’m in my late 20’s currently racing 5k every weekend around low 18’s trying to break sub 18. typical week would include about 30 miles and look something like this-
    mon – intervals 12 x 400 or 6 x 800 or 5 x 1000 etc.. once a week total miles 6 with w/u c/d
    tue – rest/ weights
    wed – 5 miles easy
    thur – 5 miles tempo
    fri – rest / core
    sat – 5 k race 6 miles total with wu/cd
    sun – 10 miles easy.

    sum weeks may vary but always include my interval and my race. last few months i have dropped the 5k race and raced some longer tougher cross country’s.
    my last interval session i did 6 x 1000 with 400 jog recovery all between 3:33 and 3:35 pace didn’t feel i had gone 100% on any.
    3:33 would be a 17:45 5K so why am i only running between 18:15/30ish every week, i’m i being inpatient? i’m i racing to much? and i’m i not puting enough aerobic miles in?

    sorry for the long post and all the questions just seem to be hitting a brick wall at the minute.

  6. Thank you for all the information you presented about running. I read two of the articles. To tell you about my situation, i am a 3000 meters runner. I have the record of 12:00, but it was for last year. I have done many aerobic and anaerobic exercises during this past year, but haven’t taken any new record struggles in order to clear the newer time. I guess the new record would be around 11:30. Could you please let me know how i can prepare better for a race which will take place in one month from now? the attendees of the race are close to me, so they are not so hard to be competed, but after winning that race i will have a closer race with more professional runners, so I should be prepared.
    Besides, i just wanted to know if i am doing the appropriate training? i mean according to my age which is 30 (i am male) ,i don’t know if i can make it any better or can i compete with professional runners if i train as they do? I just wish to clear my vision and i am confident that i can accept not being able to do so.

    • Hi Dakota, these numbers work for everyone! Regardless of age, the energy source of aerobic/anaerobic contributions are the same. It is based off you as an individual (although slightly different for male vs. female). Hope that helps 🙂

  7. I’ve just come across a number of your articles that have answered questions I’ve had bugging me in my head for a long time! I am still a little confused though..
    I’m coming to the conclusion that I must be running too fast or anaerobically in the majority of my runs. (I habitually tend to run a variety of between 4k – 12k ‘s 3 or 4 times during a normal week, and have done for the past three years).
    I usually wear a heart rate monitor, and am very aware of heart rate zones and subsequent training zones. (I’m 24, so using the 220-age formula I take it that 196 is my MHR. For the majority of my runs, even though they don’t feel too taxing and I can sustain the pace for a while, my heart rate will usually be in the 170s, often 180s. If a hill is involved it easily gets to the 190s, The park run 5k can see if raise over 200bpm (which obviously feels like hard work!!) But still sustainable for the duration of the race. So this is the bit I’m confused on.. it would seem that my heart rate monitor and the rules would seem to think I was on the brink of some sort of cardiac event the majority of the time!! Well no, but it would certainly suggest I was working way too hard, and anaerobically for too much of the time. But if anaerobic is deemed unsustainable due to lactic acid build up etc, how can I maintain running at these really high heart rates? Is the formula either not accurate for some people, or am I genuinely doing the old ticked a hell of a lot of damage always running in these zones, despite feeling great and really enjoying the runs (not 190-200bpm) but certainly at 170s, 180s I feel fine!
    I’m coming to the conclusion that even though I don’t understand this, the answer is to tone it back for the majority of my running. Today I tried a much slower pace (it felt painfully slow just piddling along!) and kept my heart rate at approx 150. It definitely felt very comfortable, and not really getting me out of breath much. But became more enjoyable as I started to accept this new pace! Am I right in hoping that if I ensure the majority of my running is kept in this zone, with perhaps one speed/interval session a week, then with time I can start to move back up to the pacing I prefer to be at, but without the heart rate monitor thinking I’m about to keel over?
    And have I been working ‘anaerobically’ but somehow sustaining it for a long period, or is my aerobic zone not correlating with the traditional heart rate zones?
    Sorry this is a very long question, I have been going round in circles with this query for over two years, and your articles have finally helped to answer a lot of it!
    Thank you!

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