Triathlon is a world that has a constant flow of buzzwords, fads, and hacks.

Every month there is some new way to get yourself faster. Often it’s marketing a product that you probably don’t actually need, and sometimes it’s a method that has been around for decades but has re-emerged with a fancy new name or terminology.

Recent years have seen a big increase in the popularity of MAF training, by not only its founder/inventor (more on him shortly), but also as a tool used by other endurance sport coaches.

In this article we are going to talk about MAF training, what it is exactly, how it works, and some of the potential flaws and misconceptions behind it.


MAF training is a training system/philosphy developed by Dr. Phil Maffetone in the 1980s.

Dr Maffetone was a pioneer of heart rate training and worked with legends including 6 time Kona winner Mark Allen.

He no doubt has a wealth of knowledge and experience, and has helped many people achieve amazing things.


MAF training is a way of training at a specific low intenisty.

MAF actually stands for Maximum Aerobic Function.

You find this intensity using the MAF 180 Formula.

Here is how:

    Subtract your age from 180, then modify from one of the categories below:

    • If you have or are recovering from a major illness (heart disease, any operation or hospital stay, etc.), are in rehabilitation, are on any regular medication, or are in Stage 3 (chronic) overtraining (burnout), subtract an additional 10.
    • If you are injured, have regressed or not improved in training (such as poor MAF Tests) or competition, get more than two colds, flu or other infections per year, have seasonal allergies or asthma, are overfat, are in Stage 1 or 2 of overtraining, or if you have been inconsistent, just starting, or just getting back into training, subtract an additional 5.
    • If you have been training consistently (at least four times weekly) for up to two years without any of the problems mentioned in a) or b), no modification is necessary (use 180 minus age as your MAF HR).
    • If you have been training for more than two years without any of the problems listed above, have made progress in your MAF Tests, improved competitively and are without injury, add 5.
    Dr Phil Maffetone

    What does this number mean?

    The end number is an athlete’s maximum aerobic heart rate. Thanks to the MAF 180 Formula, all athletes can now obtain their ideal individual aerobic training rates.

    Dr Phil Maffetone

    Except…. is it really?

    Actually, what it is in reality, is a generic formula attempting to guess at an athlete’s maximum aerobic function.

    In reality things might be a little (or very) different.

    Here are some examples of coached athletes showing their MAF HR vs the actual top of their aerobic zone:

    (mixture of lab tests and feild tests used to figure Actual HR Zone)

    As you can see – we have many differences. Some above, some below, some by a little bit, and some by quite a large margin.

    So its very possible you could use the MAF calculation and be in completely the wrong intensity range. Of course the opposite is true, it might figure out just right!

    Although our sample above is very small with only 10 athletes, the formula does seem to set the HR target too low for female athletes.

    This could be due to the fact females tend to have slightly higher heart rates than males in general.

    Related read: 

    These days it is generally accepted that the formula of 220 minus your age to find your maximum heart rate is out-dated, yet people still seem to think that a generic calculation could be used to find other parameters?

    wait, So it’s not useful?

    Yes and no.

    We definitely want to be doing a lot of our training at an aerobic intensity. The amount will vary widely based on how many hours the athlete trains, the event they are training for, and what you are trying to achieve in the training phase.

    But how we find our aerobic intensity could be individualised to the person in a much smarter way than a generic calculation.

    MAF could be a good starting point to play around with certainly, and for many people it’ll be just fine!

    But if you find that you can’t sustain your MAF HR, or if you find that you are almost walking (and have a good training history), then there is a good chance you may be using a number that is not correct or you.

    There are lots of alternative ways to set an aerobic intensity:

    • Use how you feel (RPE) – you should be able to just about hold a comfortable conversation (full sentences!)
    • Nose breathing – you should be able to do this intensity with your mouth closed
    • Figure out your Z2/Aerobic Heart Rate using a threshold feild test
    • Get a lab test
    • Have a coach who figures it out for you


    If you are going much slower/easier than you need to be then you may gradually start to lose fitness over time. We need to give the body enough stimulus to create change. 

    If you are going much faster/harder than you should be then you you might end up over-trained or with a lack of aerobic fitness.

    If its just out by a little bit… it’ll probably all be fine really.



     We all need to include plenty of aerobic training (and plenty of faster training too!) in our schedules.

    There are many ways to decide what we define as aerobic training intensity (some might be more personalised than others!).

    Choose one and stick with it. (for more than a few weeks!)

    If it works, great, if it doesn’t, try something different.


    It’s probably great for attempting to set a target for mass groups of people.

    But if you are trying to coach an individual, or set your own individual training, then you can probably do a little better.

    (in our opinion of course 😉)