MAF Training - Low Heart Rate Training

HR watch

MAF Training stands for Maximum Aerobic Function Training.  You my have heard the phrase " Run slow to run fast", well that is where MAF training comes in.

If any of the following resonates with you, MAF training might be perfect for you:

  • You are a new runner.
  • You are an older runner.
  • You often have running related injuries.
  • You want to reducing your running injury risk.
  • You are less enthusiastic about running than you used to be.
  • You dread speed work.
  • Your race times have slowed or you are just not improving.
  • You lead a stressful lifestyle.
  • You want to improve your overall health.
  • You are gaining weight in spite of extra exercise.

The Basics of MAF Training

MAF training is a philosophy invented by Dr Phil Maffetone and along with it, he wrote the hugely popular book, The Big Book of Endurance Training and Racing.

It is actually a coincidence that his surname beings with the letters MAF.

The theory behind MAF training, is to build up your aerobic base so that your body can learn to run faster and faster at a lower HR.  This delays the time when your body needs to use the anaerobic system, which means you can run longer and faster before your body begins to tire. 

With MAF Training, you run by HEART RATE as opposed to speed and pace.

Many people don't realise, but all races from 800 m upwards use a combination of aerobic and anaerobic energy.  Within that there is also a comfort zone and a critical zone. The critical zone is usually where races are won or lost.

The longer the race the more you rely on your aerobic system, so it makes sense to develop it using MAF training. However for shorter races, strengthening your aerobic system, means you can rely on it more and so you delay moving into your critical zone. This is why developing a strong aerobic base is so important.

Confused about aerobic and anaerobic? 

MAF training not only results in you running faster at a lower heart rate, but it also helps develop lots of other systems in the body. These include:

  • Your heart muscle gets stronger.
  • Your mitochondria (the parts of cells that turn the sugars, fats and proteins that we eat, into forms of usable chemical energy) increase, which means more energy for your muscles.
  • Your physical stress levels decrease.
  • You mostly burn fat for energy instead of carbohydrates, so it is a great way of training if you need to lose a few pounds or that flabby belly.
  • Since there is less stress on your body, you can run for longer. This is great if you are training for a semi marathon or longer endurance event.

Aerobic vs Anaerobic - why they are important

We have 2 systems in our body for providing energy. The aerobic system and the anaerobic system. 

What people don't realise, is that research shows that doing most of your running in your aerobic zone (around 80%), is the safest and most efficient way of training your body.

Aerobic system:

The aerobic ("with oxygen") system, uses oxygen to convert fat to energy in order to power your muscles. This system relies on an abundant supply of mitochondria (the part of the cell which converts nutrients to energy).  Our body has a huge fat store (even skinny people), so with a well developed aerobic system, you can keep on running for a very long time.

Anaerobic system:

The anaerobic ("without oxygen") system comes into play when there is not enough oxygen for your needs. For example, when you are running hard and fast, you are using up oxygen faster than you are taking it in.  In order to create the energy that you need, your muscles start to break down their supply of sugar (glucose). The anaerobic system tires quickly and your body glucose levels are in limited supply, so you cannot run very long using your anaerobic system.

Calculating your MAF Heart Rate

MAF training is centered around your MAF heart rate. Using a specific formula based on age and current health, you calculate your MAF heart rate and then you do ALL your training runs (to begin with) based on your HR. Your HR and time on your feet are the most important aspects. Forget pace and speed.

As a general rule your MAF heart rate is 180 minus your age. 

So if for example, you are aged 50 and are in good health, then your MAF heart rate will be 180-50 = 130.  Your MAF range for training will thus be 120-130 beats per minute. 

Here's how to properly calculate your HR using the MAF formula.

My MAF Training Experience

Before I started MAF training I had been running for about 3 years. I trained like most other people around me. Train hard, train fast and push yourself as much as you can. At first, I improved and got faster and was regularly placed in the top 3 for my age group during races. However, my improvement and physical health soon started to crumble.

I seemed to be getting frequent injuries whether it was my Achilles or my IT band or something else and my race times were not improving. In fact, they were regressing with having to take time off on a regular basis.

Gradually my runs became less and less enjoyable and I started to dread the faster workouts or my long runs. I knew then it was time to change my training method, as after all I did really want to enjoy running again.

In November 2015, I discovered MAF training. I bought Dr Phil Maffetone's book, read it over and over and then began my journey of  very slow training.

At first, the average pace that I could run whilst keeping my heart rate at or below 125 (my MAF heart rate), was 15:17 minutes/mile or 9:30 minutes/km. Slow.

I could only run or shuffle on the flat and any slight incline, like stepping up a pavement or a small slope, meant I had to walk to keep my HR down. My aerobic system was obviously pretty poorly developed.

I was so embarrassed by my slow shuffle, that I would purposely find running routes where I wouldn't meet anyone that I knew and I avoided putting my runs up on Garmin.

I was also not sure if this whole MAF thing was going to work for me. I didn't know anyone who did it, as it was just something I had discovered on the internet. It was kind of an experiment that I "hoped" would work.

However, as the months went on, I suddenly realized that I was getting faster but at the same heart rate. It took a while mind you and I understood now why everyone on the forums said to give it at least 6 months. 

After 6 months of "MAF-ING", the racing season started. I was pretty panicked and nearly backed out of my first race as I wasn't sure how my body was going to cope. I had done next to no traditional speed work, whilst everyone around me had been sweating their guts out doing intervals and tempo runs.

However, when my first race was over I was a total convert to MAF. Not only had my legs not forgotten how to move fast but they were faster than before and I didn't once have that feeling that my lungs were exploding or that my heart was going to jump out of my mouth. Since then I have got personal bests in 5km, 10km and half marathon distances.

Fast forward a few years and I am still a MAF convert. I have rekindled my love of running, I enjoy my runs, I have the time to appreciate my surroundings and best of all I am injury free. I also don't get home knackered and feel like I need to eat the contents of my fridge.

You may be wondering whether you have to do MAF training all the time and forever. That depends on what your goals are. If you are happy running slower, are enjoying the benefits and are feeling in good health, than perfect, stay with MAF.

For me, who likes to do races from 5 km upwards, I personally do also need to stress my body with some speed-work every now and then. This gives me a mental boost more than anything, but does also remind my muscles that they can run fast if they want to.

I currently do a base period of only MAF training during the winter months when I am not training for any races. So this could be say a 4 month block. Then when the racing season is starting, I will incorporate some speed work but not more than 20% of my total weekly running time.

To help me not overdo the 20%, I use Matt Fitzgerald's 80/20 running plans as they tie in perfectly with the MAF training method.

Getting started with MAF Training

The best thing to do is to take your time to read up about it.  Below are the 2 books that I suggest you read first. 

Got a question about MAF training?

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MAF Running Questions asked by others

Click below to see contributions from other visitors to this page...

Walk faster than run! 
Hello, I used to run by feelings.. on race(5K or10K)as fast as i can...and my HR is 180bpm at 6-6:30 min/km. I do MAF for 1 month now (54 female)... …

Heart rate zones using the 80/20 Plans 
When you are using the 80/20 training plans how do you setup your heart rate zones especially for the speed work? My understanding is that 80/20 uses …

Running a marathon at maf  
I am running the London Marathon in April. I’m just wondering if I should run the marathon at my MAF or maybe slightly lower? Nicole's Reply: Hi Wes, …

Slowing speed 
I’m into the second week of MAF & my speed is going down continuously though I have stabilised more into my heart rate of 132. During initial run my heart …

Improvements period, 10km race , marathon race and hills training. 
How long does it take on average to see improvements on MAF training method 2. Can I race a 10km after 4months in this training only. 3. Can I run …

Heart Rate During Race 
I have been on MAF training for 3 months now, and my average weekly mileage is 30 - 50 km. Based on the monthly MAF test in the past 3 months, I could …

Heart rate goes over MAF when hiking 
Thanks for your info. I can’t seem to hike without my heart rate getting over the max, the trails can be steep here. Will the hiking over max HR impede …

MAF training  
Just started the MAF training. In your experience, how long did it take you before you could run consistently without walking? I need some encouragement! …

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