MAF training is the training philosophy developed by Dr. Phil Maffetone, coach of six-time Ironman Hawaii World Champion Mark Allen back in the ’90s. The philosophy was born out of Maffetone’s observation that many endurance athletes were frequently becoming ill and getting injured as a result of pushing their bodies to incredible levels of stress in training.  With a view to improving athlete’s health, Maffetone created his revolutionary philosophy which, in my experience, is a real game changer. Although there is a certain romance in the athlete pounding round the athletics track – legs screaming, lungs burning, sweat dripping from the brow – is it necessarily the most efficient method of achieving peak athletic performance?

Using heart-rate as an indicator of how hard the body is working, or bio-feedback, Maffetone observed his patients and found a definite threshold at which the body could run aerobically, burning fat as an energy source, and then an anaerobic system, where above this threshold the body would switch to primarily burn sugar. He called this threshold the Maximum Aerobic Function (MAF) heart rate. As any endurance event – or activity longer than a few minutes – relies heavily on the aerobic system, it is intuitive to infer that efficient training of this aerobic system would generate improved racing performance. This is the basis of the Maffetone Method.

But it’s not only targeted training of the aerobic system that benefits the endurance athlete. Training below this MAF threshold could help the body become more efficient at burning fat for energy, allowing you to train and race for longer, at higher intensities before hitting the dreaded energy wall, where the body practically runs out of usable fuel.  With the human body only able to store a small amount of sugar as glycogen, an efficient fat-burner could twin a fat-burning and sugar-burning engine to harness a much greater amount of energy, using both bodily stores of energy, unlocking new realms of performance.

How do I calculate my MAF?

Based on analysis of his athletes, Maffetone created his 180 formula. Advancing the age-old,  often inaccurate, method of finding your maximum heart rate (220 – your age), Phil established that 180- your age gave a good estimate of the level at which your body could maximally exercise aerobically. Once you have found 180 – your age, there are various caveats for adding or subtracting 5-10 beats depending on your background fitness, frequency of illness (amongst others) to establish your MAF. To calculate your MAF, visit For me personally, I did 180-20, then took an additional 5 beats as I had had more than two colds/bouts of flu over the past year. This left me with a MAF of 155bpm. A range of 10beats below your MAF, up to your MAF is the optimum training range according to Phil (for me, 145-155bpm).  This optimum training range spans across all your training, no matter whether you are swimming, cycling, running, kayaking, rowing, whatever. The rationale for this is heart-rate is a communicator of the stress the body is under, and so no matter what activity you’re using the same heart, the same aerobic cardiovascular system.  This training range provides maximum aerobic stimulation across all sports, key to unlocking endurance performance potential.

Is this a joke? How can I work out at that heart-rate?

A common issue for people investigating the Maffetone is that their MAF can seem incredibly low compared to the rest of their training. Where a lot of athletes are coming from high-intensity, interval-based training plans, where they smash themselves to bits night-in, night-out, the MAF method can seem too easy, too slow. And initially, that could seem to be true. For me, my first couple of seasons in triathlon had been largely interval-based, with most (all) training taking place at target race-pace or above race-pace. At the time, this was 6.52 min/mile as I targeted a sub 1hr30 half-marathon. Starting with my MAF, I dropped to nearer 9min/mile pace on 2-3 mile runs, with some of the slower miles being at 9.30min/mile. This felt incredibly slow, and frustrating, as I’d had a not too recently set a new 5k PB at 6.01min/mile pace. However, I persevered. From only running a couple of miles at 9min/mile pace in July 2015, I was able to run a half-marathon at 7.57min/mile in October, just 84 days later, all at the same heart rate – an improvement of almost a minute per mile. The transformation was incredible.  To read more about my personal progress, visit ‘The Results’ page.

For some, training at MAF may require you to walk instead of run to start off with. If this isn’t appealing then you can get creative with your training. As I too was frustrated with running/walking so slowly and calling it ‘training’, I took to getting out on my bike more. I found it difficult to get my heart rate into my optimum training range of 145-155bpm, so felt as though as I was getting a tough workout in whilst getting the same aerobic training benefit. At points I had to do aerobic intervals, and do periods of 2-5 minutes in my training range, and then had recovery periods in between of a few minutes before going again. This enabled me to build leg power and keep up my strength, whilst getting optimum aerobic training – still keeping the romance of being a hard-working, push-yourself-to-the-limit kind of athlete. It kept training fun. If cycling isn’t your thing, try swimming. Then you have to work even harder to get your heart rate into your training range!

For more ideas on keeping training interesting and fun for the initial tough weeks, check out my blog page for ways I keep sessions varied.


In order to maximise the efficiency and benefit of aerobic, fat-burning training there are aspects of diet that Maffetone recommends changing.  As well as the standard eat more veg and fruit, cut the junk food type stuff, the MAF method turns the nutrition war against sugary, processed, refined foods. Whereas most athletes will make carbohydrates like bread, pasta and cereals the foundation of their diet, the MAF method calls for a increase in healthy fats to make up the bulk of our meals.

You may be thinking at this point, that this Maf dude is crazy. To become a prime athlete, I should be running super-slowly, and eating fatty foods? Surely, I’m just going to get slower and put on weight.

But before you stop reading and decide Maffetone is a total whack-job, listen to this. When the body breaks down carbohydrate in the form of cereals, white bread and pasta etc., the carbohydrate becomes a sugar. When this sugar enters the bloodstream, and causes a spike in blood-sugar levels and energy, the body releases the hormone insulin to reduce blood sugar, and often has to store the unused, excess sugar as fat. Therefore, an athlete who avoids fats and stocks up on carbs to avoid weight gain, is actually not necessarily helping themselves. Once inside the body, the excess carbohydrates will be stored as fat. Fats play a key role in hormone production and controlling inflammatory responses amongst various other things; they’re not to be skipped on. Plus they taste great. If I to choose between a high-fat/low-carb diet, and a high-carb/low-fat, and having experienced both, I’d choose high fat everyday. If you’re not convinced about the sugar vs. fat debate,  check out ‘Fed Up’, a documentary on Netflix the topic of sugar in obesity – it’s an interesting watch.

For full details of Phil’s views on diet and sugar specifically visit:

For details on my nutrition plan my blog page or the ‘recipes’ section.

The Biggest Benefit

Running slower and eating better, with fewer sugars, has in my opinion, had one major effect on my life, training and performance. It is the consistency at which I can now train. Training slower (at first), at my MAF heart-rate, I put my body under less stress and avoided the illnesses and colds that I was regularly picking up in my previous seasons doing triathlon. Also, the slower running helped improve my running form. I was no longer under such strain to put out such power when training, and so my body adjusted to a better, smoother technique. Through this adjustment I have managed to avoid those pesky niggles and injuries I had been picking up before (knee, achilles, hip, back injuries to name a few).  The diet changes meant I had much more energy too, so felt I could get out and train more and needed less recovery time. Quickly after starting with the MAF method, I felt able to train twice a day, around full-time studies, and later around full-time work. Fewer sugars in my diet also meant fewer spikes and dropouts in energy, enabling me to feel as though I had the energy to go and work out.  All these changes brought about by discovering, and committing to the Maffetone Method have allowed me to train with great consistency improving my weight-loss, health and performance.

To give a quick example: I’ve been running without injury or illness for 8 months now, and in the past 4 months I’ve seen my MAF run pace drop from 8.40min/mile over 3 miles to 7.06 min/mile over 17miles at the same heart-rate. The 17 mile run was before breakfast, with no water or nutrition during the run, primarily using the fat-burn engine I’ve been developing with the MAF method.  It’s not just me who is seeing these benefits, when I read some of the stories on I knew I had to investigate the MAF Method further.

For information on how to kick-start MAF training check out the ‘Base Training’ page.