The Maffetone Formula, Running Slow & Burning Fat... Some Current Thoughts

A couple of weeks ago, we posted a blog about endurance metabolism and how 'burning fat' can help to boost your performance. You can read the full blog by GOING HERE. This week, we're continuing that theme with our current thoughts on fat burning, Maffetone formula and endurance performance.

Why do we do a long slow run?

As far as I'm concerned, there are 3 main reasons for doing a long slow run and these are as follows:

1. Conditioning - Your legs deal with a great amount of impact every time they hit the ground which causes muscle damage. The only way to stop this breakdown and general wear and tear, is to spend 'time on your feet' so your body becomes accustomed to repeated movements and foot strikes. It doesn't matter how big your engine is, if your legs are internally bleeding and your chassis is collapsing at the 18 mile point, your marathon PB is going out of the window. The long run should also be 'specific', for example, downhill running causes greater damage than flat running and carrying a 'pack' adds extra weight and further damage. If you're training for a mountain running event, running a flat route without your pack isn't specific enough. Put this in simple terms, look at the runners in the final miles of an Ironman or ultra race, very few of them look out of breath. It's not their aerobic fitness which is stopping them running in the latter miles of such endurance challenges, their legs are simply 'smashed'.

2. Metabolic Adaptation - Your muscle fibres will adapt and more closely resemble the 'slow twitch variety'. One of the key changes is the ability to use fat as a fuel source and also to use less energy overall. These combined changes mean that you are less likely to run out of carbohydrate during longer distance events. We are more likely to use fat as a fuel source at lower intensities, as we exercise harder, we switch to carbohydrates as a preferred fuel.

3. Mental Adaptation - If you enter an Ironman or ultra running race and it's likely to be 12 hours in length, that's a long time to keep moving forwards. If your longest session is generally never more than 3 hours, you can be sure that by the time you reach 6 hours in the race and realise that you're only half way.... it's going to be difficult to remain in a positive frame of mind for the remainder of the race. Sports psychologists would call this 'familiarisation' but it's just common sense.

If you look at all of the 3 points above, the slower you run, the more you achieve each objective. If you run at a slower pace, you can run for longer and spend more time on your feet, use more fat and become mentally adapted to long periods of time.  In particular, those people who are struggling to get up to 'target distance', whether that's 20 miles for marathon training or beyond for ultra, you probably just need to slow down.

The most common 'long run error' is people running too hard and as a result, they struggle to complete the full distance. Worse still, they can't walk for the next 3 days and miss out on other critical sessions.

If we were to rank the 3 things above in order of importance for performance, I'd say that 'conditioning' is the main benefit of long distance running. That's the most likely thing to limit your performance, with metabolic and psychological adaptations coming 2nd and a close 3rd. The reason it's important to highlight this, is because EVERYONE talks about 'fat burning' as if it's a silver bullet for performance.

The reality is that in most ultra type endurance events, you can get enough fuel, but as we mentioned earlier, your legs are just smashed.

So how slow should I run?

It's very common for endurance athletes to get the 'training zone' thing very wrong, they drift ino the habit of doing easy stuff too hard and then the hard stuff is too easy. It's far more common for athletes to run 'too quickly' on long runs, it's very rare that they are running too slow.

Most runners have a 'Sunday pace' which they naturally 'slip into' and this is generally a bit too quick. A run of 16-18 miles often leaves them tired for a couple of days and going further than 18 can often require a great deal of recovery. Marathon runners stepping up to Ultra struggle a great deal with this concept. They can't calculate how they can run for 12-24 hours, when a normal 3 hours run will leave then tired for the next 48 hours. The answer is simple, you can slow down, you can even walk.... it's ok.

It is very hard to break the habit as our Sunday run pace is hard ingrained in our brains. It's our natural and comfortable 'steady running pace'. Try and run a little slower and you'll soon find, unless you are concentrating, that you'll just drift back to Sunday pace that you are accustomed to.

What is the Maffetone Formula?

Maffetone formula is a calculation to estimate your aerobic threshold. You can find your aerobic threshold by doing a VO2 test, but without access, Maffetone formula is your next step.

What's aerobic threshold?

It's the point at which you go from being able to hold a full conversation, to having to hold a broken conversation during exercise. It's generally Zone 1 / 2 for most people. Alternatively a good guess is the intensity at which you can no longer breathe through your nose and have to use your mouth.

What's the Formula?

1. Subtract your age from 180

2. If you have been training consistently (at least four times weekly) for up to two years without any of the problems just mentioned, keep the number (180–age) the same.

3. If you have been training for more than two years without any of the problems listed above, and have made progress in competition without injury, add 5.

Once a maximum aerobic heart rate is found, a training range from this heart rate to 10 beats below could be used as a training range. For example, if an athlete’s maximum aerobic heart rate is determined to be 145, that person’s aerobic training zone would be 135 to 145 bpm.

Practicalities of Maffetone

1. We've used Maffetone formula many times in recent years for coaching purposes, but I'm starting to back away from it for 1 simple reason... it's over complicated. We believe that athletes commonly do their easy stuff too hard and their hard stuff too easy, so we encourage them to slow down for all easy rides and runs.

It should be quite a simple thing to understand... 'run at conversation pace'. However, people seem so out of touch with their perceived effort that asking them to run easy / at conversation pace, is too difficult a task for them to accomplish. As a result, we find ourselves completing either a physiological assessment or mathematical calculation, which can be used as a reference point. We then input this reference point into a watch and tell them to keep a close eye on their watch and to not go over the calculated figure.

I understand for those with less experience, that learning intensities is something they need to achieve, but how complicated does this need to be? Run easy, so you can hold a full conversation, when your breathing rises so your conversation become more difficult, slow down. Do we need a complicated equation, 4 blogs and 6 podcasts to understand conversation pace?

2. A lot of people like and embrace Maffetone because it's easy. I see a lot of posts on social media about how Maffetone is great, but rarely see posts about the opposite end of the spectrum, doing hard interval work. The point is doing the easy stuff easy, is that you can do the hard stuff hard. I'm not surprised that Maffetone is so widely embraced, it can give people a soft option.

3. One of the key benefits of Maffetone being 'low intensity' is that you can do more volume. It's a simple principle introduced by Arthur Lydiard in the 1950's (the inventor of long slow distance or LSD), if you run slowly, you can run more and maximise volume. Running at a slow pace / Maffetone pace for 2-3 x 30 minute runs per week is of little benefit, doing 40 miles plus per week is where the training stress starts to take shape. If you can't commit to that kind of mileage, you'd be better spending your time completing a mixture of low and high intensity training.

4. There's a big focus on 'burning fat' rather than carbohydrates. From our experience of testing over 1000 athletes, the biggest and quickest way to change your metabolism is to change your diet. Simply doing long slow runs / rides to enhance fat burning (whether fasted or not) may have some impact, but simple diet changes can have a much bigger impact.

5. 20 years ago, all marathon athletes ate a high carbohydrate diet. Now, there seems to be a real trend for high fat and low carb (LCHF). It's important to point out that overall marathon standards were better 20 years ago than they are now. Whilst I'm not suggesting high carb is better, it clearly wasn't detrimental for everyone.

We have an issue with 'diet culture' in the UK, mainly with it being 'all or nothing'. If someone is following a 'diet' and has one bad day a week, they feel as though it's all been wasted. It's all or nothing and there's no ground in between. You can see the same trend with athletes, switching from high carbohydrate and low fat to low carbohydrate and high fat, from one end of the spectrum to another. It's important to step back and understand that there is a 'middle ground' between the two and you don't have to be one of the 2 extremes.

In our next blog we'll take a closer look at diet and what we've seen over the last 10 years in terms of diet changes, trends and performance.

If you'd like a more accurate assessment of your personal strengths and weaknesses, you can book a sports science assessment. We can put together a plan which will be specific to you, the cost for sports science assessment is £80. We also offer 121 coaching for triathlon and ultra running, starting at only £40 per month. Email for more information.

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