MAF Training review – Part 4 The Myth of MAF

To borrow from Douglas Adams, my “MAF training review” is now a trilogy in four parts! Previously I looked at Maffetone’s methods and training (part 1), detailed my own experience (part 2) and then gave you my thoughts on it what’s good about it, what the issues are and whether it’s a good way to train for running (part 3).

If you haven’t yet read the links give them a go, but for now just know when I tried MAF training I ran for 5+ months, logged 200+ hours of training where only 4½ hours was spent above a heart-rate of 138bpm. This heart-rate was determined using Maffetone’s age-related formula that I can see no scientific basis to explain. I can’t say I got any notable benefit from the training as I could run a 21-min parkrun before I started and, at the end of it I was running 20:39. In the midst of it, I did run 19:52 but regressed after doing some sprints and drills on a coaching course.

The training itself was demoralizingly slow and I was always fearful of the heart-rate monitor beeping at me to slow down because I’d exceeded the maximum heart-rate. I said I’d never train with it again because it was so unenjoyable and because there are better ways to train.

Today I’m going to prove there are better ways to train to get the same benefits.

Six months of non-MAF training

Let’s roll back to November 29th at the end of last year when I ran my standard Sunday long run to Broadstone in 1:39:26. It’s an average pace of 8:31/mile and my heart was pumping away at an average of 148 beats per minute. Six months later, May 30th, I ran it again, a minute slower, but my heart-rate was now only 131bpm. That’s a drop of 17 beats and an indicator that I’ve improved my aerobic system.

Regular readers will know I’ve spent the intervening six months training for 800m following a plan from one of Jack Daniels’ books. Although I know much about coaching and how to train I’ve never tried middle distance before, so I decided to see how one of the world’s best coaches approaches it and see what I could learn.

As I’ve documented in monthly updates – January, February, March, April  – I logged 40-45 miles per week with a mix of easy runs, long runs, intervals and threshold runs. The training got tough in the depths of winter but I got through it. I ran every day and while I got tight at times, I never got ill or injured. By April I was ready to test out my new found fitness and was highly surprised when I only achieved a 3-second improvement!

Nonetheless a few days after a second 800m time trial I ran my Broadstone route a minute faster (1:38:38) than in December and was now averaging a heart-rate of 140 – eight beats lower. So I’d done nothing like Maffetone training and improved by his measures.

I suspected the poor time trial results were due to a lack of endurance and embarked on six consecutive weeks of nearly fifty miles through April and May as I documented in my May 800m update. When I ran another 800m time trial it was still about the same at 2:53, a five second improvement over six months ago, but the rest of my running was feeling easier. My easy runs had sped up but more notably I broke 1hr30 on the Broadstone run in training. An improvement of ten minutes for a nearly twelve mile run.

What would MAF suggest?

Seven years ago at age forty-two, when I tried my MAF training experiment, I calculated a MAF-HR of 138. But actually, given I was coming off an illness, I possibly should have taken ten beats off and used 128bpm which would have made things even harder and certainly slower.

Being older, Maffetone would suggest I now train to a lower heart-rate than I did last time around. At forty-nine this gives an initial MAF-HR of 131 but I’ve been running daily since late 2019 without issue. According to MAF you need to have trained for two years without issue to be allowed to add a further five beats, but for this comparison I’m going to do it anyway and analyse my recent training against a MAF-HR at 136bpm. This may sound like a cheat but if I used the lower figure, the stats would skew even more against MAF training.

If you’re wondering why I’m calculating my current MAF-HR when I said I was never going to use MAF training again, it’s purely to analyse the recent training I did and show I improved despite not following any of the low heart-rate training that MAF recommends.

Recent training

What follows is a look at my training for the six weeks after my mid-April time trial. There are one or two miles missing where I was coaching or giving a Personal Training session, as well as a couple of days where I didn’t wear my heart-rate monitor but the bulk of the training is shown.

The general format of each week:

  • Eight mile Steady runs on Tuesdays and Fridays with a ½-mile warm-up / cooldown aiming to run at my threshold.
  • On Sundays the Broadstone long run, usually at the crack of dawn, again pushing it along and throwing in some strides along the way.
  • The other four days of the week I aimed for a forty minute recovery run.

With six consecutive 50-mile weeks, this block of training totalled 300+ miles and 42 hours.

Yet when you break down all this running, twice as much time was spent running in excess of my MAF-HR (136) as below it. (Note: there is a small issue with the software I used to total the Above-Below durations because it double-counts heart-rates of 136-137 into both categories. The actual figures were 28 hours above MAF-HR, 14hr45 below it but only 41hr50 total run time).

You can see in the graph below the length of each run in time and the proportion of it spent above or below MAF-HR. The yellow is the time spent exceeding it and accounts for 65% of running time. Almost every day I was exceeding MAF-HR for some of the run – that can’t be good according to Maffetone.

Now take a look at the graph of 2014’s MAF training where I only exceeded the MAF-HR for 2% of the time. You can barely see any yellow in the early weeks and it doesn’t increase a whole lot. In the graph above, I often spent more time above MAF-HR in a single run than I did in a week then.

Graph of MAF weekly MAF training in 2014

It’s not even close. It’s very clear I was constantly breaking the MAF-HR in my recent training and not just by one or two beats as happened back in 2014, but by large margins.

Here’s a graph of the time I spent in excess of 150 on those runs. You can see I was regularly running for over 45-mins with heart-rates on the Steady and Long runs that were nowhere close to MAF-HR. I was effectively training to the MAF-HR of someone over twenty years younger than me.

Recent training – blue lines showing time spent running at 150+ heart-rate

What’s amazing is I accumulated twelve hours of running at over 150HR which isn’t much less than the nearly fifteen hours I ran below my recommended MAF-HR of 136. Yet somehow I got exceedingly better results than when I trained to MAF-HR in 2014.

Getting faster

Not only was I seeing improved heart-rates, my effort runs were improving too.

The November run was my fastest time on the Broadstone course at 1:39:26 and with the 800m training this had reduced to 1:34:03 by March. On 2nd May I reduced it to 1:32:55 then on May 23rd took it down further to 1:29:15. The average heart-rate on this final run was 149 which is only one beat higher than when I was running it in late November. Then my fastest single mile was ripping along down Gravel Hill at 7:52, by late May I was sub-7 with a 6:58.

On the Steady runs I only have one comparator. Back on November. I ran a local 7 ½ mile course round Merley which took 58min52 at an average pace of 7:54/mile and the fastest mile was 7:33.  In mid-May, during a spell of high winds I decided against going to the beach and opted to run the local route in 20mph winds. The run came in two minutes quicker at a pace of 7:38/mile with the fastest mile now at 7:08 along with a couple more showing in at 7:18 and 7:21. At the beach, I’ve begun to see miles in the 7:05-10 range. There’s no doubt I’m speeding up and if I were racing longer distances I’d certainly see better times.

Better ways to train

I’ve loved the past six months of training for all the reasons I hated the MAF training. I got to run fast, sometimes I even got to sprint as fast as I could. I rarely looked at my heart-rate while I was running and I certainly didn’t have the heart-rate monitor beeping at me to slow down. The variety of paces and training sessions kept me interested as well as nervously excited on occasions.

I haven’t cracked the 800m yet but I’m confident training is going in the right direction to get there. I’ve seen improvement and I’m running faster than six months ago with heart-rates at slower speeds being lower. That’s an indication the body is improving its fat-burning capability. I’ve been sleeping deeper, got leaner, faster and remained healthy and injury free which are the sorts of reasons Maffetone puts forward for following his method.

The premise of MAF training is that to improve fat-burning you have to run at low heart-rates and stop eating carbs. I did neither of those. Across six months I regularly hit higher heart-rates and I never restricted my diet or stopped eating carbs – if anything I’ve eaten more during the winter months with two bags of Doritos each week and regular cakes from the bakery. Yet I proved it’s possible to achieve the promised benefits of MAF training despite regularly breaking the heart-rate that it suggests a man of my age should use.

None of this was achieved by sticking to a heart-rate calculated from my age and is why I put no stock in MAF training as a system in itself. I believe there may be applications for it in certain circumstances but not general training.

I’d love to hear people’s comments and questions about this block of training and my MAF training review. All reasonable scepticism or thoughts are welcome!

MAF Training review – Part 3 The Good, The Bad and The Ugly

In this final part of my series on MAF training, I’m going to give you my thoughts on it as a way of training. In part 1 I discussed how the real Maffetone Method is a holistic system for living but most people are only interested in the low heart-rate training formula. In part 2, I plodded through my experience of nearly six months’ worth of MAF low heart-rate training. Now I look at what’s right and wrong with this as a training system. Let’s get critiquing …

My own experience with MAF training was not very positive and within this post, I’ll explain why. But my aim is not solely to run MAF training down, I don’t see Maffetone as some kind of salesman selling snake oil or a “get quick rich” scheme – he knows about health. As a chiropractor of many years’ experience there are some good things to be learned from his book and there are certainly some athletes who have had success working with him. So let’s begin by seeing what we can gain by understanding his work.

What MAF can teach you

Benefit 1 – Understanding Aerobic and Anaerobic training is very useful

Maffetone explains training can be fuelled in two ways – aerobically and anaerobically. Aerobic uses oxygen and is very efficient, anaerobic works independently of oxygen which causes fuel to burn quicker and creates waste products that limit or fatigue you.

While anaerobic energy enables you to hit your top speeds – after all sprinting uses it extensively, Maffetone explains the detriments of training anaerobically. It increases the acidity of the body, requires more energy and can have major downsides in terms of poor sleep, appetite, weight among other things.

Understanding that too much anaerobic training at the expense of aerobic training is an important concept to grasp and is quantified these days in Stephen Seiler’s 80:20 rule. Perhaps because Seiler’s research only appeared recently, the older MAF low heart-rate training is proposing something closer to a 100:0 ratio.

Benefit 2 – Understand the Aerobic/Anaerobic threshold

Scientists will tell you there is no definable “Threshold” where you cut over from aerobic to anaerobic mechanism. Your exercise is always fuelled by a mixture of both. While this is technically true, the reality to you as a runner, is there are times when it’s clear you’re relying on one type more than the other. Stephen Seiler found research indicating most sub-elite runners are training anaerobically 70% of the time and need to bring this down to 20%.

Benefit 3 – The premise behind lower heart-rate training is right

I remember while running Bournemouth Bay Half Marathon in April 1996, commenting to a chap running alongside me that my heart-rate was averaging 177bpm and he replied “That sounds rather high”. We were only running at about eight and a half minute miles and I went on to finish in 1hr51. This is exactly the sort of heart-rate that people Maffetone met were always training at, and what MAF training is designed to address and bring down. Had I been successful in getting lower heart-rates, I would have seen my half marathon times begin to improve. That’s what MAF low heart-rate training is all about and why the premise is right.

At the other end of the scale, I’ve run at nine minute mile pace with my friend Simon, who is a 2hr34 marathoner and his heart-rate was only 110bpm. That’s the heart-rate of a man who has built his aerobic system and is burning fat.

Somewhere between these two extremes lies the aforementioned threshold between aerobic and anaerobic where you want to do much of your training. MAF suggests this occurs at a heart-rate that is calculated using your age but as I’ll explain later, I don’t. The premise is correct, very low heart-rates e.g. 110bpm are burning fat; heart-rates up in the 180s are burning sugar, or more correctly the glycogen and glucose that is sugar-based. Training somewhere between these two endpoints will lead to effective training.

Benefit 4 – Warm-ups are great

Maffetone devotes a section of the book to getting athletes to spend at least twelve minutes warming up. Genuine warm-ups are one of the most under-rated things in distance running training.

Most people start their runs quickly and then slow down to a pace which feels comfortable. The problem is that by starting fast they activate lots of anaerobic, sugar-burning muscle fibres which are then able to kick in every time they’re needed. This is one of the reason why people say they can’t run slowly. Those anaerobic muscle fibres are the thing that cause high heart-rates.

If you start a run slowly, you only use as many muscle fibres as you need to get the job done and can stay aerobic much more easily. This is reflected in lower heart-rates and focuses the training on building the aerobic system.

Benefit 5 – Low HR training can teach you the feel of Easy runs

Most coaches agree “running your easy runs too fast” is the number one mistake runners make and it’s not even limited to amateur athletes. Even elite athletes can do it and send themselves into a spiral of overtraining and underperformance.

If you pay attention to how easy your low heart-rate training runs feel then you can begin to understand just how easy they need to be. Remember easy is a feeling not a pace.

Benefit 6 – MAF Method would probably help with the “obesity crisis”

While MAF makes no claim on this I found when I built my aerobic base up (using my own method) I stopped being hungry. I still ate carbohydrates but I could return from an 18-mile early Sunday morning run at 8min/mile pace, eat a bagel and banana and then not get hungry until the afternoon. I actually found myself having to schedule meals to avoid missing them! My lifelong desire for cake, crisps and sweets which had been a large part of my diet naturally ebbed away. It returns whenever I start to train more anaerobically.

When you consider there’s a sizeable proportion of the population who don’t do regular exercise, and they get out of breath quickly when they do, it suggests their aerobic systems are underdeveloped. If their aerobic systems are underdeveloped then they’re going anaerobic in even the simplest activities and they’re burning up sugars from the muscles which need to be replaced. This leaves them hungry and prone to eating quick-fix sugary food to sate their appetite.

If people were to develop their aerobic system then they could go about their day-to-day activities without ever needing to dip into anaerobic energy at all. This would give all the benefits Maffetone details around not revving up the central nervous system and getting stressed. It would lead to better fat-burning for fuelling activities and avoid hunger.

My doubts about MAF training

I’m looking here almost exclusively at training to a heart-rate determined by the age-related formula. That’s the part that’s grabbing most people’s attention and they’re promoting as MAF training. (It occurs to me as I write this that I’ve been referring to it as “low heart-rate training” which of course it probably isn’t for anyone in their twenties but allow me that indulgence).

A) The science behind the formula is debateable at best

At its simplest the MAF formula is suggesting that as you get older, you get better at burning fat. But, to my knowledge, there is no known mechanism to suggest all 20-year-olds will burn fat at 160HR, 30-year-olds at 150HR, 40-year-olds at 140HR, 50-year-olds at 130HR and 60-year-olds at 120HR. Even with the small 5-10 beat adjustments these numbers have no scientific basis.

I’m inclined to believe he’s substituted age for experience.

Typically a 50-year-old runner with thirty-plus years of experience will have a bigger aerobic base than a 20-year-old runner and this is why training at lower heart-rates may be better for them. The latter’s youthfulness does give them the ability to engage high levels of muscle which push the heart-rate higher than an older runner who, with the natural decline from ageing, has lost some top-end speed.

While the human body declines with ageing, it is not so abrupt that a forty year-old needs to train at twenty beats lower than a twenty year old. At close to age fifty, I’m running aerobically at 150HR where the formula predicts I shouldn’t run quicker than 130HR.

B) Maffetone defines aerobic exercise as fat-burning and anaerobic as sugar-burning

While this is a good simplification, it’s nothing like the science. It’s accurate to say the anaerobic system is sugar-burning but the aerobic system is a mix of fats and sugars. It’s possible to build an Aerobic system that is burning high levels of sugars – this is a process called Aerobic Glycolysis (also known as Slow Glycolysis) and generally equates to your marathon pace.

In fairness to Maffetone he does hint that some of the aerobic system’s energy will come from sugar – for example on p.23 he shows Mike Pigg running at 127HR as getting 30% of his energy from sugar. It’s when Pigg gets to 153HR that he’s beginning to go 50-50 between fats and sugars.

It’s difficult to get the body to pure fat-burning other than by being careful about what you eat. This is why a significant part of the bigger Maffetone Method (not just low heart-rate training) has you looking at your nutrition and trying a two week no refined carbs regime. But if you change your diet to remove most of the sugars then you don’t need to train to a heart-rate as you only have fats available to burn.

C) Fat-burning is only required for long distance events

Building the aerobic system is important for all distance runners but fat-burning (remember the aerobic system can also be sugar-burning) is only useful for racing events lasting longer than 1 – 1½ hours. That means twenty mile races, marathons and ultras.

Fat-burning can be useful for half marathons but when your times are closer to the top end of the field then you’re unlikely to run out of glycogen stores. If you’re running middle-distance, parkruns or 10Ks fat-burning isn’t going to help your race times.

It can be useful to develop your fat-burning for training runs as this leaves your glycogen stores in tact for harder efforts. This is especially true for cyclists and triathletes who do many more hours of training and therefore find it easier to deplete their glycogen stores (i.e. bonk or “hit the wall”) and these athletes seem to have made up a significant portion of Maffetone’s clientele.

Basically, fat-burning is unnecessary for racing the shorter distances but building a strong aerobic system, mainly based on aerobic glycolysis, is important.

If you’re a young runner training to a high MAF-HR then you aren’t solely working on fat-burning, you’re working on improving aerobic glycolysis. The MAF training will work but not because you’re fat-burning as he suggests.

D) Older runners can struggle with low heart-rate training

When I was forty-two, I trained to a MAF-HR of 138bpm which usually meant running no faster than 9min/mile. As I’ll show in a future post, my current training has progressed by running at heart-rates in the high 140s and 150s which are far in excess of my MAF-HR.

To progress you have to train at the point just before you start to increase the use of anaerobic energy (reread Benefit #2). This has variously been called the Anaerobic Threshold, Aerobic Threshold and Lactate Threshold among other names. It doesn’t matter what it’s called but it does matter that you’re training at it if you want to get faster.

As she approached age thirty, Paula Radcliffe was setting the world record for the women’s marathon, an event which is run almost exclusively using aerobic energy. She was running at heart-rates in excess of 180 where a MAF-HR would have limited her to 160-165 bpm.  Imagine therefore how limiting it can be for the oldest runners expected to train at 120-130 heart-rates but won’t see any improvement if their threshold heart-rate is higher.

E) It’s tough on Fast-Twitch runners

You may have heard of fast-twitch and slow-twitch muscle which are respectively good for speed and endurance. While slow-twitch is perfect for aerobic exercise, fast-twitch naturally works anaerobically and requires extensive development to improve aerobically. Even then it is less efficient than slow-twitch muscle and can easily switch back to anaerobic mechanism. This is the reason why after a weekend of sprints and drills, my own MAF training went backwards.

Of course, this is why heavily fast-twitch runners are better suited to sprints and shorter distance events. But even a mile world record holder like Peter Snell could run a marathon in under 2hr40 despite sitting down at the side of the road and taking a rest break after the first twenty miles! It’s not impossible to build a good aerobic base with fast-twitch muscle just harder and it’ll usually incur higher heart-rates which makes the MAF age-based formula less appropriate.

Naturally fast-twitch runners will retain FT muscle longer into old age so when you combine this with the previous point (D) you can see why I struggled with MAF training and why others may too.

Note this is why MAF training will likely work very well for slow-twitch runners who naturally run with low heart-rates and actually struggle to get their heart-rates up. They can push harder on all their runs without exceeding MAF-HR (unless they’re Paula Radcliffe) without going particularly anaerobic. But then they don’t particularly need a heart-rate monitor to hold them back.

F) Female runners may struggle with it

The female runners whose training I’ve observed tend to run with higher heart-rates and certainly this was the case for Paula Radcliffe (see last paragraph of point D).

In his book “Better Training for Distance Runners”, Peter Coe states that women tend to have higher heart-rates because their hearts are physiologically smaller and therefore pump less blood with each stroke which is compensated for by beating quicker.

Maffetone makes no distinction in his system for male or female runners or those who have higher maximum heart-rates. He’s very clear that maximum heart-rate don’t matter.

G) MAF training is not a system for training a beginner

It’s likely that if you try to run below a MAF-HR as a beginner runner you will quickly be exceeding it at all but the slowest pace. This could especially be the case if any of the previous three points apply.

At age 47, I got injured and after a three month layoff I resumed training. In my first week I was barely able to run ten minutes per mile without finishing runs at heart-rates in the 160s. I generally took my runs as easy as I could and my parkrun time was under twenty-four minutes after a month but I was rarely running below my MAF-HR. If I had stuck to a MAF-HR, there’s no way I’d have been at that level after a month and running sub-1hr40 half marathons six months later.

H) MAF training says nothing about volumes of training

While the book focuses on the intensity of your runs, it doesn’t give any concrete information about how much training to do; only in broad terms about “less is more”.

I dived in and did too much relative to my ability with 8-10 hours each week but I’d read elsewhere that low heart-training allows you to do as much you want. It turns out I simply didn’t need to be doing that much training.

How much you should do depend on what your body can take. When you’re beginning, you only need relatively short runs to create a training effect. A couple of hours spread out through the week will have a big effect. I currently train from 5-7 hours each week and get decent benefits from it. My friend Simon, the 2hr34 marathoner trains closer to 10 hours each week.

I) MAF training is not a speed system, it is about creating speed endurance

Although MAF training promises to get you faster, more often than not it’s helping you to race longer distances faster. It’s a subtle distinction. What I mean is that while you might be able to run one mile all-out in eight minutes, MAF training will simply enable you to build the endurance to do a parkrun or 10K at this pace but you won’t necessarily be able to run a single mile faster. That will only happen when you do some speed training. If you only ever do low heart-rate training, you’re eventually going to come up against a brick wall of no improvement.

This is why my first three months of Maffetone training saw no improvement in their average pace but why after I did a parkrun, it picked up – the parkrun acted as a speed session because I went all-out at it and my natural fast-twitch muscle kicked in.

If you never work on your speed side you’re never going to reach your potential. Maffetone does allow for some anaerobic interval workouts but you’ll only know this if you read the book. There’s not much details on these intervals and speed workouts or how they relate to different race distances.

Real world problems with MAF training

I’ve observed many runners who get enthusiastic about MAF low heart-rate training but I struggle to think of anyone who has benefited from its long term possibilities. This isn’t necessarily because MAF training is flawed but because the runners following it, don’t really follow it. Here are the common issues I see.

i) Runners don’t follow MAF training long enough to see the benefits

The aim of the MAF training is to build the aerobic system and this happens by the body improving the aerobic capabilities of slow and fast-twitch muscle. Biologically, muscle fibres start to grow more mitochondria which improve the use of oxygen; meanwhile the capillary network that supplies oxygen from the arteries to the muscle fibres becomes more extensive. It is these changes that allow cells to extract and use more oxygen from each beat of the heart hence why it then needs to beat less frequently to deliver the same oxygen levels.

The process for growing new mitochondria and capillaries takes six weeks so this is the minimum timeframe you should be focused on MAF training if you’re to get its benefits. But it’s not necessarily a one-off hit as you’ll usually be growing these on a rolling basis. So while the training you do in week 3 is reinforcing the growth that started a few weeks ago, it is also initiating further growth that will be realised in week 9. This is why the elites can stay in a base period for months.

However if you start racing or doing heavy speed workouts during your MAF training period, which is what I tend to have seen, the full benefits may not be realised. Often there’ll be a small improvement but not as good as they might have been had they committed. I’ve even seen suggestion that capillary beds can be destroyed if too much speedwork is done but I’m not sure how true this is.

The people I see raving about MAF training on Youtube, the web or Strava never seem to follow the system for a period of months like I did. It’s a fad for them. Invariably they follow it for some of their runs each week but then throw in a race or workout regularly. This is contrary to the idea of MAF training which, I believe, is supposed to be a continuous process.

They might as well go follow a marathon training plan and get the same benefits from high mileage and minimal speedwork

ii) Runners don’t actually stay below the calculated heart-rate

When I MAF trained I was dedicated to staying below the MAF-HR. I don’t see the same zealousness from other runners. Most of those I’ve seen trying it are capable of running decent times e.g. half-marathon in 1hr25 but to stay below their MAF-HR might require them to go back to nine minute miling aka “running too slow”. So they tend to slow their runs down to about eight minute miles and be content if their heart-rate averages the MAF-HR. Occasionally they will stop, walk or go up hills slowly but mostly they jog along doing an approximation of MAF training that doesn’t bear close scrutiny.

iii) Runners don’t use a decent heart-rate monitor

Until a decade ago all heart-rate monitors were chest straps which were usually accurate. You could get inaccuracy at the start of runs which was usually solved by giving it a lick before putting it on but otherwise they tended to be accurate.

The new generation of wrist-based heart-rate monitors are highly unreliable in their accuracy despite the manufacturers’ claims and any inaccuracy is usually put on the runner for not wearing the watch correctly. I’ve seen countless examples where runners have heart-rates in the 180s while jogging and then when they start doing fast intervals the heart-rate drops to the 140s. That’s a physical impossibility. The wrist-based monitors often lock onto a runner’s cadence but there may be other reasons behind their inaccuracy.

Whatever the reason I would only trust a chest strap heart-rate monitor from the current technology available. It may improve and there may be some which are already reliable so if you choose to go wrist-based, test it before you rely on it. And do that test under a variety of conditions, not just sitting on your sofa or walking to the local shop.

iv) Runners don’t do the warm-up

Runners who try MAF training almost always start their runs fast, only slowing down after a minute as the anaerobic boost runs out and they start to puff. The problem is they’ve then engaged more muscle than they can run aerobically with, this makes it much harder to stay under MAF-HR.

To compensate for increased anaerobic energy usage, the body invokes lactic clearance therefore that’s what they’re training rather than signalling to the body a need to adapt aerobically. Once lactate clearance kicks in, it’s possible to be running anaerobically and still see lower heart-rates.

A secondary issue of starting runs without a warm-up is heart-rate monitors can read inaccurately at the beginning of runs and this causes big headaches if the heart-rate monitor is constantly beeping say you’re running too fast. It often takes 8-10 minutes to settle down and has disrupted your rhythm if you’re trying to stay below a certain heart-rate. I used to worry on my MAF runs if my heart-rate was up in the 140s early on not knowing whether it was me running too fast or the monitor reading wrong.

As I explained earlier, Maffetone recommends doing a fifteen minute warm-up which helps to avoid these issues. Many of the MAF training advocates don’t have the patience or knowledge to do this.

The BIG flaw to MAF training

Heart-rate monitors don’t show the levels of lactate in the blood.

As I wrote back in Point D (and will reproduce here to save you scrolling back up): To progress you have to train at the point just before you start to increase the use of anaerobic energy. This has variously been called the Anaerobic Threshold, Aerobic Threshold and Lactate Threshold among other names. It doesn’t matter what it’s called but it does matter that you’re training at it if you want to get faster.

Most people understand the principle of Threshold training so I won’t go into depth about it. What I will point out is while there are various ways of identifying what the heart-rate at threshold is, only Maffetone suggests it is related to age. And quite simply – it isn’t.

It can vary drastically depending on your training. I have seen myself running at Threshold heart-rates of 127bpm after doing excessive amounts of speedwork yet two months later it’s up at 150bpm. There was no relationship between my age and Threshold heart-rate in those numbers and there won’t be in anyone else – other than by coincidence.

In well-trained runners the Threshold heart-rate is more consistent. Mine is usually somewhere around 152-153bpm when I’m running well. Coach Peter Coe said lab testing shows it’s usually around 150bpm in male runners but higher in women. Mike Pigg, who I mentioned earlier appears to be around 153bpm. I would be very careful about using a generic value like this to specifically define the Threshold but with experience you may be able to define where your own starts.

There are very few, if any, elite runners these days who train to heart-rate. If they do it’s usually to ensure their recovery runs are slow enough. If they are doing workouts by heart-rate, it’s likely they’ve derived their numbers either by taking lactate samples or by using heart-rates experienced in races. An age-based formula won’t identify it.

In my opinion, if you really want to train to heart-rate, you’re better off going with a catch-all number of 150 (or 160-170 for a woman) and see how your body reacts to it. I would aim to run recovery runs at least fifteen beats lower than this but not get too tied into staying exactly below or on the numbers. I’d look to do a warm-up that takes at least ten minutes to get close to my target heart-rate but I’d let my body guide me on how it wants to run. If I began to go over the target heart-rate then I wouldn’t be too concerned by a few beats but I would look to ease off and get back under target. I would aim to run the 150HR rate efforts no more than three times per week with the low heart-rate recovery runs on the other days.

That’s if I was going to train to heart-rate which I don’t.

Summing up MAF training

The idea of training to build an aerobic base is a good one for anyone involved in endurance sports. Whether this needs to be fat-burning or sugar-burning depends on the distance(s) you intend to race.

But the fundamental concept of using an age-related formula to decide on what heart-rate to train at is high flawed. There is no proven mechanism that reliably explains why a 40-year-old runner should train twenty beats lower than a 20-year-old runner.

Remember Phil Maffetone was a health practitioner who treated all sorts of endurance athletes so being a running coach was never his speciality. What the MAF method does well is to (re)build a healthy aerobic system. This allows runners to peak their training with anaerobic training for better race times, but MAF training itself is not a system for building top end speed. You will only go as fast in races as your top end speed allows. If you spend months creating a super-efficient aerobic system, it opens up the space to access speed at the top. If you never do speedwork you won’t be any faster over short distances but you will improve over longer ones.

While many of his clients found great success from following his methods, the success stories he details are of already-elite athletes in their respective long distance events. They were already fast and well-developed, MAF training just took them the final steps of their journey. For example, Mark Allen was placing in the top 5 of the Hawaii Ironman before he met Maffetone. He became a six-time champion when he improved his aerobic system because fat-burning is crucial in an event lasting over eight hours.

What Maffetone showed these athletes is how to build the aerobic system which is the foundation of endurance. That is half of running. The other half is the anaerobic system which helps create speed. Following the Maffetone approach as a complete running system is like listening to researchers who tell you that you can get faster by building VO2max through High Intensity Interval Training (HIIT). It’s only half the job. Good running coaches already understand how to combine these two halves of aerobic and anaerobic training to create endurance and speed to maximise the potential of a runner. It’s often self-coached runners who have fixated on one half or the other who profit when they introduce the other type of training.

If you go through Maffetone’s Big Book you will find all the athletes he gives specific details for are elite (i.e. they already have top end speed) and they are under thirty which gives them a higher MAF-HR to work with. It’s for this reason I repeat my belief that the Maffetone formula is a blunt instrument which could as effectively be replaced by a catch-all heart-rate limit of 150 beats per minute for male runners and perhaps 10-20 beats higher for women. The specific value you use would likely need to be individualised and decided upon once you’ve got used to your own typical values.

There are better ways to train than MAF training to be the best runner you can. These involve mixing periods of short intervals, long intervals, continuous runs, long runs and easy runs at a variety of paces to develop both speed and endurance.

Update – since publishing this, I wrote a further post proving my point about there being better ways to train. In it, I detail how I trained regularly breaking my proposed MAF-HR, often training to one the equivalent of someone twenty years younger than me yet still made progress. Read Part 4 here.

MAF Training review – Part 2 My Experience

Today I continue my in-depth review of MAF training with a look back at how it went for me in the summer of 2014. In part 1 of this series, I explained most people promote the Maffetone Method as low heart-training, but it’s actually a holistic system including re-evaluating your diet by taking a two week break from refined carbohydrates. I too was in the heretic camp and went with the low heart-rate training only. I didn’t change my diet or try any of the other things Dr Phil Maffetone recommends, partly because if I gave up carbs I wouldn’t have anything left to eat. I read a copy of his book while I was doing the training and was trying to make sense of it as I was going along.

This wasn’t my first experience of low heart-rate training, that occurred over twenty-five years ago as I recounted in this post about John Douillard’s Body, Mind and Sport book. Using “Darth Vader” diaphragmatic nose-breathing, while running to a sub-130 heart-rate, I saw no success at getting faster or achieving the effortless flow state he promised but I kept trying. It was only when I got good at running through pace-based training that I began to see the low heart-rates promised by Douillard. But the idea of low heart-rate training stuck with me and somehow I read about Maffetone training and when the opportunity arose I decided to give it a dedicated shot.

My first two years of committed running (2011-13) saw me recording personal bests at all distances raced but something was missing which was stopping me from hitting the heights I hoped for. I didn’t quite know what it was but the combination of The Redgrave Paradox, a return from a winter virus and wanting to try new things led me to give MAF training a try.

The winter virus knocked my training back for two months and while, I’d missed the half marathon I was aiming for, I was still running capable of running twenty-one minutes at parkrun. With the virus over I began to bulk up training with four mile runs in the morning and another thirty minutes of barefoot running in the evening.

In early May I clocked forty-three minutes at Lymington 10K. A week later I jogged round Bournemouth parkrun in 25:43 with heart-rate averaging 141bpm but hitting a max of 155bpm. I’m not sure why but, that evening I decided to try MAF training. I was 42-years-old, the formula gave me 138bpm and in the past I’d always found my running felt very comfortable at this level. When I was building my first aerobic base three years earlier it was where my heart-rate naturally seemed to fall on easy runs.

Beginnings – May and June

I followed the MAF low HR regime religiously. The first Sunday long run was hellish because I picked a hilly route. I must have stopped and walked thirty times to keep my heart-rate down on the hills but I managed the twelve miles without going over the limit. It was slow at 10:24/mile with the fastest mile being 9:40 and the long uphill into Broadstone taking over eleven minutes. The following week was even slower but I stuck with it. Like all spiritual adepts there were times where I unintentionally fell off the pew and I did have one deliberation exception; at the end of some runs I would do a 150m sprint back to my house. It sent my heart-rate soaring and those moments are not included in any of the stats that follow.

In the first six weeks of training I ran, on average, for eight hours and fifteen minutes covering fifty-five miles yet only spending 1min35 above my MAF-HR of 138. I’m doubtful it’s possible to do any better than this. By the end of June I’d accumulated fifty hours of training but less than ten minutes of it exceeded MAF-HR.

Total time8hr 18min8hr 44min7hr 18min9hr 23min8hr 48min8hr 36min49hr 34min
Above MAF-HR1min071min013min272min193 secs1min289min25

Most days I was running morning and evening yet what’s incredible is, while I was accumulating all this, I still took Fridays off as a rest day. I’m sure that helped parkrun to feel good on a Saturday morning. Monday to Thursday mornings were a shoed run with a barefoot run round a local field in the evening. At weekends, the evening run was shoed. Here’s a sample week from this period.

Time runMileageAvg paceTime above
Monday00:41:414.5Morning run9:22 / mile
00:30:383.6Evening (barefoot)8:31 / mile
Tuesday00:41:064.5Morning run9:14 / mile7 seconds
00:31:033.6Evening (barefoot)8:38 / mile
Wednesday00:41:354.5Morning run9:21 / mile
00:30:273.6Evening (barefoot)8:27 / mile
Thursday00:43:104.5Morning run9:42 / mile8 seconds
00:30:523.6Evening (barefoot)8:34 / mile
Saturday00:31:154.5Bournemouth parkrun9:42 / mile11 seconds
00:34:393.6Evening recovery9:36 / mile
Sunday01:59:5111.7Morning long run10:16 / mile35 seconds
00:34:283.5Evening recovery9:50 / mile

Going further – July into August

In July I decided to change tack. I was still going to train to MAF-HR but the arrangement of my week would be different. The barefoot running had to come to an end. It was a long, hot summer and through June the ground began to harden up. It eventually became like running on concrete and my body simply couldn’t handle it. One thing I’ve haven’t yet been able to sort out in my running is not being a loud and noisy runner who hammers their feet into the ground. I know one guy who can run half marathons comfortably in a pair of Vibram Five Fingers on tarmac but I can’t do it for more than a few yards.

Part of my experimental mindset also wanted to see what would happen if I ran longer distances so rather than splitting my training day into two runs, I usually only ran once but much further.

Below is a training week which totalled 67+ miles and 10+ hours while only exceeding my MAF-HR for nine minutes. This particular week, my Bournemouth parkrun time scraped under twenty-seven minutes compared to the thirty-one minutes when I started. This was as fast as it ever got during MAF-HR training and it stabilised in the twenty-seven minute range in the following weeks.

Time runMileageAvg paceTime above
Monday01:15:478.1Daily run9:18 / mile1min 23secs
Tuesday01:50:4411.7Daily run9:30 / mile4min 15secs
Wednesday01:14:228.2Daily run9:07 / mile12 seconds
Thursday01:52:0911.7Morning run9:37 / mile
00:36:374Evening recovery9:09 / mile12 seconds
Saturday00:26:525.7Bournemouth parkrun8:39 / mile2min 15secs
00:32:383.8Evening recovery8:35 / mile
Sunday02:11:5914.1Long run9:22 / mile44secs

Many people who try low-HR training say they can’t run slowly. Part of it is they go off too fast but sometimes it’s their ego complaining. I never cared if people saw me running slowly. If anyone asked why I was jogging round at the back of parkrun I’d patiently explain the MAF training system with its focus on improving fat-burning over sugar-burning and then get on with doing my thing.

One of the reasons I stayed motivated was I knew the general approach of the elites is to do a block of ten weeks building their base. Sometimes they do this for longer but either way, the idea of replicating this helped me to overcome any doubt I was feeling when results weren’t showing up plus I had a reward in store to delay the gratification. When I’d completed three months of MAF training, I’d go to Poole parkrun and run all-out.

Even though I was completing Bournemouth parkrun 3-4 minutes faster, over those three months there was barely any improvement to my average weekly pace – it was always a few seconds faster or slower than 9:15/mile. The graph below shows this and the one notably slow week was when I totalled 77+ miles!

The reading I’d done suggested it would take three months for the aerobic base to be built. Not knowing better and not seeing any gradual improvement, I took it to be a timeframe where new speed or pace would appear at the end of it.

It therefore came as vindication when I ran Poole parkrun in 19:52 and I was very pleased to break twenty minutes. I’d been running twenty-one minutes before I started and I’d knocked a minute off with training. I now had the encouragement to continue on and see where this system could take me.

Peak experience – August into September

In the week following the parkrun my average pace improved to 8:51/mile – almost thirty seconds quicker. And it stayed there for the next three weeks. I thought I was finally beginning to see the promised gains and even put in occasional barefoot runs around the field again. These were proving quite efficient and I could run nine minutes with heart-rate averaging 115bpm. At my best I ran a sub-25 5K barefoot round the field without exceeding MAF-HR.

My Sunday long runs to Pamphill and back, which had originally been over ten minute miles, were now breaking nine minutes and I was even seeing a sub-8 mile on the downhill into Wimborne. The MAF training all seemed like it was going in the right direction.

Part of my year’s plan had been to do my UK Athletics coaching courses and I’d become a Leader in Running Fitness in May. The next level up, the Coach in Running Fitness course began with a full weekend in Exeter and meant I wasn’t going to be able to do my usual MAF training runs but I wasn’t too concerned as I figured a short rest would help. Over the two days we did many short practical sessions, both coaching and being coached by our partners but nothing extensive. We weren’t sent on one hour runs or anything, just technical drills, jogs and sprints and while my heart-rate was higher on the Sunday morning I thought nothing of it. I couldn’t get out of doing the practicals but I thought it would also be a test of MAF training’s effectiveness, no runner should have to be so perfect in their training if a system works.

Collapse – September into October

On the Monday morning I woke up … eventually. I’d slept for twelve hours, 10pm – 10am, and still felt exhausted. I played it safe and took the day off from running and resumed the next day. While the first couple of miles were ok, by the end of the run I was slowing my pace drastically to avoid breaking the MAF-HR.

Over a weekend I’d gone from being able to run over eight miles in 1hr10 to barely more than seven. In pace terms it had dropped by a minute per mile (8:38 to 9:40/mile pace). It clawed back slightly over the next four weeks but never back to where it had been. It was still an improvement over where it had been in June and July but not at the late August peak. I was still putting in the effort with weeks of 65, 63, 59 and 58 miles but the pace was often the wrong side of 9min/miles.

Enough – October into November and December

I was beginning to lose faith and needed to know where I was at, so in mid-October I went back to Poole parkrun. I’d run 19:52 nine weeks earlier but now I could only achieve 20:39. It had all fallen apart with one weekend of non-MAF training. I felt disheartened and ready to give up. I’d never truly seen the improvement that seems to be promised by low heart-rate training and I couldn’t see myself shuffling through months of my watch beeping at me.

I was scrabbling around for explanations and diving back into the Maffetone book I began to wonder if the increased heart-rates I was seeing were due to overtraining. It can be one of the signs and MAF’s recommendation for overtraining is to cut your training volume back. So this is what I did. All that happened was it became increasingly harder to run to MAF-HR off less and less training.

I was left wondering whether the previous winter’s virus had flared up again even though I otherwise felt fine. I took more and more rest days logging only 55-60 miles in each of November and December; mileages which had once been my weekly exercise had now become monthly. I was done with MAF training. I’d started it in May, shuffled around for months and not got anywhere closer to the best running I’d done in the preceding years. I felt like I was always waiting for it to come to fruition and it never did.

Looking back

Within this post, I’ve tried to sum up my training for people to understand what I experienced while avoiding getting bogged down in the details. Even now I feel it’s quite stat-heavy. Every run I did that summer is recorded in Garmin and on spreadsheets. So many of the runs are virtually identical in their splits, heart-rates and times that there’s little to be gained from reproducing them, a summation seems enough.

I’m split between saying MAF-training worked and saying it didn’t. Unfortunately I didn’t have an outright benchmark to compare between when I started training and the all-out August parkrun that clocked in at 19:52. I think it was an improvement but I’d been capable of running this sort of time in February before I got hit by a virus.

The first question mark is when you look at my average weekly pace over those first three months it doesn’t change. It’s always somewhere around 9:15/mile. It’s hard to make a perfect comparison because I changed routes from the beginning of July but whenever the opening miles were along the same paths, the splits were very similar. It suggests I wasn’t getting any improvement from the MAF training.

It was after the 19:52 Poole parkrun that things picked up. The pace of my Sunday runs were notably quicker than they’d been in May when I was trudging up hills taking over eleven minutes for a mile.

The trouble is the fast parkrun seems to have been the trigger for this improvement and that isn’t part of the MAF training. The whole theory of MAF training is that you will get quicker simply by running below MAF-HR. [It should be pointed out the book allows you to add in some Anaerobic Intervals from time to time, but if you follow what the Youtubers say it’s simply about low HR training. Once you start mixing aerobic and anaerobic work you’re heading back towards conventional training methods.]

The second big question mark about my MAF training is what happened after my run coaching course. I went backwards and never reached the same heights of the 19:52 parkrun again. If you look at it over the whole five months of training there was no improvement – I was capable of running 21-mins at parkrun before, I ran 20:39 after.

I believe I adhered to MAF training as well as anyone could or should be expected to. I logged hundreds of miles in over 200 hours of training at slow paces. In almost six months I only totalled 4½ hours above a heart-rate of 138bpm and that includes two 20-minute parkruns where it was averaging high 160s. The graph below shows the time running with the yellow blocks representing the small percentage of time spent in excess of my MAF-HR. You can barely see any yellow in the first six weeks which reflects how well I was following the system.

What my stats don’t include are the occasional 30-second sprints I did at the end of training runs two or three times each week, or what occurred on my run coaching course. If this were a true scientific experiment they would be question marks against the validity of what I did, but with over 98% of my training as MAF expects I don’t believe they should be the difference maker to its effectiveness.

The biggest disappointment of having followed the MAF training system for all those months is that any gains I did make, didn’t last. I ran 1,345 miles to try and build the fat-burning system as Phil Maffetone suggests. By the time I ran parkrun on Christmas Day I was only able to achieve 21:45 with notably higher heart-rates than they’d been in August. Where I’d averaged 165 then, now I averaged 169. Where the maximum had been 174, now it was 181. In a matter of months, I’d gotten slower and my fat-burning had got worse. While I trained less in November and December, I’d have hoped the conditioning would last for longer.

But perhaps more importantly, whether I think my experiment proved MAF training works or not, here’s how I felt about it.

My overriding memory is of how much I grew to hate it,

I grew to dread the watch beeping at me to slow down.

Many hours were spent each week trudging along at paces close to 10min/mile. There was never any chance to break out and run fast, I was always trudging along barely lifting my knees or opening my stride. I was always waiting for the watch to beep. Not just a single tone but an irritating diddle-iddle-eee like a demented doorbell from the Seventies.

I enjoyed the evening runs much more but that was more down to the novelty of running barefoot laps round a field and feeling the ground fly beneath my feet. The lack of footwear reduced the energy-cost of running and my heart-rate stayed lower so I got to run faster.

But too many hours were spent trudging along in the mornings; automatically slowing down to trudge up hills; forever aware and vigilant for the beep of the watch ordering me to slow down.

While I was highly motivated to give MAF training a good shot, grasping for any sign of improvement, the slow pace meant my legs barely got out of first gear and I was repeatedly trashing the same muscles day after day. Running so many miles left them feeling hollow and lacking spring, and the lack of variety just made it unenjoyable. The only redeeming factor was that this all took place in the warm of the summer months. I’m doubtful I could have stuck with it through a cold, windy, rainy winter.

The one bright spot was the 19:52 parkrun at Poole and that was it. I believe you need more intrinsic feedback and enjoyment when you’re training hard to stay motivated through the tough times. If, for some reason, you aren’t getting that feedback then this is where having a good coach helps out. They will reassure you that you’re on track to achieve what you’re aiming for. They find ways to say “Don’t worry, it’s going to work out”, to point out any successes you haven’t noticed, or explain why the slump you’re experiencing is normal. In this respect, my years of coaching enabled me to self-coach and keep giving positive messages and reinforcement.

Knowing how my running improved in the years after, I realise I’d never use MAF training again. Its monotony and the age-related MAF-HR meant it didn’t work for me.  Becoming a slave to the beep of a watch and heart-rate monitor sucked the enthusiasm out of me.

I know, as I can show to anyone I coach, there are better ways to train. Endurance miles are an important part of the equation but not the only one. It’s possible to mix up bouts of fast and slow running in ways that allow you to get the best out of yourself and see intermediate improvement while the training comes together.

In part 3, I’ll talk further about what I believe the pros and cons of the MAF training system are. When it can work, what you can learn from it and what the issues are.

MAF Training review – Part 1 An Overview

This is part one of a three part series on MAF training. This week, I’ll explain who Dr Phil Maffetone is and outline the basics of his MAF Method and training system. In part two I’ll tell you how it went for me the summer I trained to it for five months. In part three I’ll give you my critical analysis of MAF training as a training method.

Occasionally I come across runners on Strava or Youtube waxing lyrically about MAF training. If you’ve never heard of it, it’s a heartrate-based formula created by Phil Maffetone that focuses on building the aerobic system. As well as being a shortening of his name, he says MAF stands for Maximum Aerobic Function.

Phil Maffetone is a retired chiropractor who treated athletes from the 1970s onwards including triathletes like Mark Allen, runners like Marianne Dickerson and ultra-runner Stu Mittelman. Chiropractic is described on Wikipedia as being “concerned with the diagnosis and treatment of mechanical disorders of the musculoskeletal system” and this is the basis of the Maffetone Method.

While there are many articles around the web and Maffetone has an extensive website promoting his methods, the information in this series of articles is mainly drawn from his “The Big Book of Endurance Training and Racing”. It’s an attractive 500-page tome going into detail about training, its effects on human physiology and giving many examples of athletes he helped. It manages too avoid being to technical even though there is a good dose of biology thrown in. If you want insight into the human body and keeping it healthy then it’s worth a read.

Low heart-training with MAF

The core of the MAF Method, as others promote it, is low heart-rate training. At its simplest the MAF heart-rate is calculated by subtracting your age from 180 to give a maximum value that shouldn’t be exceeded. It’s not an average heart-rate to run at, it’s the heart-rate you aim to never go above. If you’re thirty years old, your MAF-HR is 180 – 30 = 150 and you try to never go over 150HR on your runs.

Depending on your recent health and training you tweak your MAF-HR by adding on, or subtracting, a few beats. For example, if you’ve been training for two years without injury or illness you can add on five beats to raise the MAF-HR you’ll be working to.

There’s a couple of exceptions anyone under sixteen should use MAF-HR of 165bpm, anyone over sixty-five may add ten beats if they’re in good health. This means almost everybody training to a MAF-HR is doing so between 125-165bpm.

The MAF test

For those who really get into MAF training there is the MAF test. Once every month, you run five miles at your MAF-HR and record the mile splits. The splits will gradually get slower but over the months you should see the overall numbers improving and your runs getting faster as the following example shows:

Mile 18:218:117:577:44
Mile 28:278:188:057:52
Mile 38:388:268:107:59
Mile 48:448:338:178:09
Mile 58:498:398:248:15
Example results from a series of MAF tests (p. 82)

Ideally you go into each test rested, warm-up prior to the test miles and run the same course under similar conditions every time to keep the comparison valid. Of course with seasonal variations, results can be affected by cold, heat, humidity and high winds but as long as you allow for this, you should see a year-on-year improvement.

The real MAF Method

Training to MAF-HR is the appealing “Train to a low heart-rate and your running will get faster” headline of MAF training. To the Youtuber and Strava disciples promoting MAF training, this is all it entails to get clicks and views.

In reality this is a cherry-picked aspect of Maffetone’s training philosophy which has the following four key points:

  1. Build a great aerobic base
  2. Eat well
  3. Reduce stress
  4. Improve brain function

As a chiropractor, his focus is on healing people and helping them to stay healthy, so he comes at this from a holistic perspective as the key points show. The focus of his training method is to get the body fuelling its exercise by burning more fat instead of carbohydrates. By staying away from sugar-based anaerobic exercise, stress remain low and the two halves of the autonomic nervous system stay in balance. Too much anaerobic leads to high levels of stress, the body kicking into “fight-or-flight” mode and all the negative effects which are seen in overtraining syndrome.

Certainly the low heart-rate training is a major aspect of the Maffetone Method but once the aerobic system is building up, it doesn’t preclude you from doing some anaerobic exercise. Beyond the evaluating what you eat and how you train; he also gives advice on foot strengthening, shoes, exercising to music, as well as how to reduce stress by setting better boundaries, staying in the present and learning relaxation techniques. To an extent, I’ve only scratched the surface in my summarising it’s a big book, that’s why it’s called “The Big Book of Endurance Training and Racing”.

Ultimately the true Maffetone Method is an extensive set of guidance aiming to help you find what will keep you healthy while training extensively. Like any good health system, it’s about learning how your own body reacts to training, to nutrition and identifying any weaknesses that need building up or eliminating. Low heart-rate training is simply the headline being attached to it.

Part 2 can be read by clicking here.