What is MAF?

The acronym MAF stands for maximum aerobic function. 

Why does MAF matter?

MAF reflects our ability to burn (oxidize) body fat for nearly unlimited energy. Reliance on fat-burning, a predominant fuel source potentially used for most of our needs, occurs in the cell’s mitochondria, found in muscles, including the heart, kidney, liver and many other areas. Fat-burning also increases production of ketone bodies, useful for energy by the brain and throughout the body, and helps keep energy high, and blood sugar and glycogen stores stable. Maximizing natural fat-burning directly improves all areas of health and fitness.

What are the elements of health and fitness which MAF addresses?

  • Training within MAF HR training zone
  • Beating sugar addiction
  • Turning on fat-burning
  • Controlling chronić inflammation
  • Managing stress

What is my MAF training zone?

Your MAF HR is determined by subtracting your age from 180.

Then modify this number by choosing one category below that best applies to you:

a. If you have or are recovering from a major illness (including any operation or hospital stay), are in rehabilitation, have been prescribed any regular medication, or are chronically overtrained, subtract an additional 10.

b. 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 acutely overtraining, or if you have been inconsistent, just beginning or returning to exercise, subtract an additional 5.

c. 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).

d. If you have been training for more than two years without any of the problems listed above, have made progress in your MAF Tests, and have improved competitively, add 5.

The resulting HR is the high end of the HR range with the low being 10 beats below. For example, a 40-year old in category b) would have an exercise range of 125-135 bpm. Users can self-select any intensity within this range.

Your coach may choose to work you to a slightly ‘adjusted’ figure in line with your goals or markers from previous sessions.

How does MAF training work?

Your MAF rate is the maximum HR you will train at. Your training zone is within the 10bpm below your MAF HR. Initially, exercising at this relatively low heart rate may be difficult but after a short time, you will feel better and your pace will quicken at that same heart rate, so you will not be exercising at that relatively slow pace for too long. In other words, you will walk, run, bike and perform all activities at faster paces. This increase in pace (or power) at the same MAF HR is also an important evaluation, called the MAF Test, that measures this progress. We include testing in your plan at regular intervals to evaluate that progress.

What if there is no or little progress?

The two most common reasons include:

  • Calculating a MAF HR which is too high. This could be due to an error in using the 180 Formula, such as choosing the wrong category.
  • Poor diet. Your diet can influence your fitness even more than exercise itself. For this reason we recommend starting with the Two Week Test to identify any carbohydrate intolerances and establish good eating habits.

What is the Two Week Test?

One of the most effective ways to quickly improve health and fitness is to determine your tolerance to carbohydrate foods. This can be personalised through the Two Week Test.

Carbohydrate intolerance occurs when we consume more sugar, starch and other carbohydrates than tolerable. The result is we store large amounts of these foods as fat, and we are unable to burn stored fat for energy.

Record your perception of your health and diet before the test to compare with your experiences during and after.

  • Avoid all of the following foods during the Two-Week Test:
  • All sugar and sugar-containing products: Includes basically anything with honey, sugar, agave, fructose, cane sugar, or syrup in its ingredient list.
  • Sweets and desserts: cake, cookies, ice cream, muffins, candy, gum, breath mints.
  • All non-caloric artificial and so-called “natural” sweeteners, including stevia.
  • Many canned and prepared fruits and veggies contain sugar or starch. Read the labels!
  • All bread, muffins, rolls and product made with flour (whole-grain, multi-grain, flaxseed, rye, gluten-free, etc).
  • All products made from corn and corn flour, including tortillas.
  • All pasta.
  • All snacks: crackers, chips, rice cakes, etc.
  • Energy bars and sports drinks.
  • Ketchup, mayo and other sauces and condiments. These often contain hidden sugars.
  • Rice: wild, brown, white, basmati, etc.
  • All other wheat and wheat products: whole wheat, farro, bulgur, khorasan, millet, etc.
  • All other grains: millet, quinoa, etc.
  • All potatoes.
  • All fruits and berries.
  • All legumes: beans, lentils, peas, chickpeas, peanuts, etc.


The MAF Method, Dr. Phil Maffetone

Athletes: Fit but Unhealthy?, Dr. Phillip Maffetone and Paul B. Laursen

Carbohydrate Intolerance and the Two Week Test

The Vegetarian and Vegan Two-Week Test