My Experience Training with the Maffetone Method
Over the last months I’ve been increasingly focused on building up a proper aerobic base in my run training. This is an important step that I largely missed when I took up the sport a few years ago. For those of you that have followed me on social through this period it will come as no surprise that what I’ve been trying to build up is a more efficient and robust zone 2. I have blended some concepts around the mitochondrial definition of zone 2 and max aerobic function (MAF), as described by Phil Maffetone.
To lock down the upper limits of your zone 2 in the most rigorous of scientific methods involves consistently testing your blood lactate levels. Zone 2, as described by Inigo San Milan in conversation with Peter Attia, is the intensity at which lactate plateaus at 2 mmol/L in the bloodstream. The intensity at which you can maintain this level of lactate is the ceiling of your zone 2. Inigo coined this ceiling the “fat max”, meaning you will preferentially utilize fatty acids as a fuel in combination with the mitochondrial dense type 1 fibres.
As lactate starts to creep up you enter zone 3, a transition zone to higher percentages of glucose and type 2 muscle fibre use which continues to increase up to zone 4 where you reach the “lactate threshold” or “anaerobic threshold” of 4mmol/L. At this point you transition away from type 1 fibres and begin to rely almost exclusively on carbs (glucose) and type 2 fibres. Fat breakdown is just too slow to provide the energy required to maintain the ATP demand.
Anyways, I have not yet purchased a lactate monitor, taking the scientific approach to measure lactate off the table for now. I have plans of getting into a lab and having some numbers taken to have a better idea as to where I stand but for now I am using a more practical method to dial in the fat oxidation of zone 2.
This concept is described as Max Aerobic Function, the 180 rule, or the Maffetone Method coined by Phil Maffetone. It lacks the scientific rigour of a lactate based zone 2 but based on his success with it and the ease of application, that is where I chose to start.
The basis is simple and uses HR instead of lactate:
180-age= max aerobic HR
For me: 180-28=152bpm.
Phil has other modifiers which can take that number up or down, which I have talked about in a different blog you can reference here. Based on that calculation I selected 150bpm as my target HR for MAF. This works out well for tracking as Strava, based on my max HR, has created a zone 2 (different from the mitochondrial zone 2) with a range of 123-153bpm.
The MAF HR and upper range of Strava zone 2 HR overlap nicely and this allows me to have a good visual of my zone 2 % when I’ve completed my run.
An improvement in MAF is an improvement in pace over a certain distance while keeping the HR at the target.
To be as accurate as possible the use of a treadmill would be ideal. You can lock in a speed and train at that speed for ‘x’ amount of time until your HR surpasses your target. At that point you can record the time it took, and then drop the speed to maintain your target and continue with this process until you’ve reached the duration of your run. In theory, you will eventually be able to maintain your start speed for the duration of your run, all while keeping your HR at or under the target. You could then increase the speed and repeat.
Things get a bit more complicated running outdoors as pacing and effort are much more impacted by wind, elevation changes, and other variables. Thus what I’ve chosen to do is pick a few different routes and consistently run them while monitoring my HR on my watch through a chest HR monitor. My pace is therefore dictated almost exclusively by my target HR. This involves a lot of checking, but it has gotten much easier over the last few months as I’m more aware of how my HR responds to the routes and so on. I’ve set a goal of maintaining my target HR for 90+% of my run which I feel is reasonable given the elevation changes and other difficulties of keeping it constant through an outdoor run.
From here it is easy to see if my pace at the end of the run has improved from previous efforts over that specific route.
My first attempts at implementing this were on a Jan 13 outdoor run. I didn’t do a good job on that one. Even though I tried to run slower I still had 60% of my run over 153bpm. It took me a week or so and a few treadmill runs to get things sorted out in my head about how slow I was going to have to go and what my starting point was.
Needless to say I was not stoked. I arbitrarily selected 6mph (6:13/km) on the treadmill and was able to maintain that pace for 25 min before my HR was consistently above 150bpm. I dropped the pace to 5.7mph and was able to finish out my 40 min run at that tempo.
Talk about eye opening… the majority of my runs from last summer were done at a pace around 4:30-4:45min/km. I was going to have to fully mentally commit to this strategy because it was really quite a shock to start. Inigo suggests at least 3 sessions a week in zone 2 training to start to move the needle in the right direction.
Edmonton got hit with a nasty cold spell so I spent a few weeks messing around on the treadmill with these concepts.
On February 4, I was able to run for 60 min @ 6mph without surpassing 150bpm.
On February 15, I was able to run for 60 min @ 6.3mph without surpassing 150bpm.
And finally on February 23 I was able to get back outside for a 7km run and did so with a pace of 6:10/km with a 90% zone 2.
One month later on March 22 I posted a 5:21/km over the same 7km stretch with a 94% Z2.
I have also have an 11km route. On Feb 27, 2021 I posted a 6:10/km avg with 87% Z2 and on March 24, 2021 over a slightly different route, but same distance, posted a 5:25/km with a 86% Z2.
I feel like the gains are coming along and there has been tangible progress using this strategy although lacking some scientific backing. I don’t have any races coming up so I will continue chipping along with this method until something is more immediately on the horizon and see what the returns are during a race.
In theory, by improving your base you should be able to utilize your aerobic system more effectively and at a higher intensity allowing you to last longer before diving into glucose stores and the fatigue that comes with it.
Anecdotally, I feel much better after these runs too (obviously because I’m not working as hard than previous years training).
I would love to get the upper limits of zone 2 dialed in a bit tighter with some concrete lab values and see how continuing to train at this HR impacts those labs over the course of the season.
Hopefully next time I check in I will have some new info! If you made it here thanks for reading!
