If I designed a study....MAF Training vs. Sweet Spot

Hi everyone! I am new to trainerroad. I am an exercise scientist fresh out of grad school with more of a clinical background than a performance background. Nonetheless, I have been diving into the literature as well as watching the ask a cycling coach podcast to gain insights on training methodologies and theories behind training intensity distributions.

As a time crunched cyclist myself, I have seen some very positive and quick progress following a sweet spot base training plan. In the past, I was all in on 80/20 polarized training. I can’t say I really understood how the philosophy translated into success for athletes other than proof of concepts. The more I keep digging into it, the more I realize that Dr. Phil Maffetone and others essentially argue that training below the first ventilatory threshold (or LT1, which requires high volume) may lead to increases in fat utilization during exercise. This is observed when runners in particular are able to see there pace times go down but they run at the same heart rates. For cyclists, it seems the concepts would be the same. Same heart rate, more power is able to be achieved at that same heart rate provided you somehow either estimate or ensure you are below LT1. My question for a potential hypothesis is this:

If you took a sweet spot plan vs a polarized plan and put them head to head, wouldn’t you expect increases in power for the same given heart rate simply because both groups became fitter? Is it because of increases in “metabolic efficiency” which relates to the amount of fat utilization during exercise. I suppose using trained and experienced cyclists would help to eliminate the issue of novice riders getting fitter regardless of training. For novices, any type of structured training is bound to get them fitter.

I think of interest to a ton of people is what ultimately raises power more for a given heart rate? Ultra endurance cyclists come to mind in this scenario. If very high volume pointed and focused training below LT1 ultimately resulted in them having a crazy wattage/ heart rate increase (lets say 50 watts) over a 4 months span, could we say this is the “best” training approach? That is what Dr. Maffetone would suggest. I am seeing top Iron Man athletes such as Lionel Sanders adapt similar training philosophies. His training is shifting to high volume and below LT1. Conversely, if you took people and put them through a sweet spot style training plan, what would their aerobic threshold heart rate do? Would the aerobic threshold (LT1) watt capability rise due to increases in fat utilization, an increase in lactate tolerance, FTP ceiling increases, or a combination of everything? For me, I think it could be a combination of metabolic and cardiac adaptations. I can’t wrap my head around how Maffetone style training seems to suggests huge metabolic changes are the primary driving force behind dropping pace times in runners at the same heart rate. For example, stroke volume increases allow for more watts at same heart rates with training and this is because athletes can supply more O2 per heart beat as they get fitter. Cardiac and plasma volume adaptations are huge driving factors behind increases in VO2 Max and FTP. I would say even more so that metabolic adaptations in some cases.

This topic sounds like a fantastic 2+ hour trainerroad podcast topic and perhaps someone can help point me towards some studies that have explored these questions or if trainerroad already has a podcast on it. Anyways, that ends the thoughts I have bouncing around in my head. I had to get out in writing. Haha!


how are you normalizing this? Time? TSS? TiZ?

I would say each individual athletes LT1 and LT2 and power zones created based on those personalized zones for each athlete.

I was too in 2016. Fresh out of a masters program that was mostly unrelated to performance. It is a totally different world and it will challenge you (hopefully in a good way, as it has me).

Other good ones are Empirical Cycling Podcast, CTS Trainright podcast, FastTalk, and my personal favorite “That Triathlon Show”. You’re going to catch on quick that this sport (like most) has little cliques and “schools of thought”. Use a healthy dose of skepticism like they should have taught you in school.

Fun stuff, but remember: intensity distributions are outputs. These ideas about percentages this and percentages that didn’t inform the training. They were observed and debated afterwards.

Yep, same idea.

This is not unique to Maffetone. All good coaches and many athletes understand and exploit this concept. However, ask yourself this question: does training at or near maximum fat utilization necessarily lead (cause and effect) to improvements in fat utilization. IOW, what about other intensities? Can I improve fat utilization by training at other intensities as well? And if so, is the emphasis on low-intensity for higher volume athletes more about fatigue management? Don’t let anyone answer those questions for you. They will try. Those questions are STILL EQUIVOCAL. Science won’t give you an answer here. But good coaching might lead you to an approach that works.

Hmmm…interesting. So maybe don’t just stick to low intensity? But lots of endurance and tempo builds aerobic fitness (by a variety of mechanisms). So I wonder how you would do as much low intensity as you can (in the hours given) while still exploiting some adaptations that come about via high intensity?

There already is one. TR introduced polarized training plans a while ago and had a podcast dedicated to the topic. FastTalk also has several on the topic (Seiler). See above note about cliques.

It’s an academic exercise. I recommend you not waste your time.

Just to drive home the idea of not putting the cart before the horse when it comes to intensity distribution, check out this article

Look across the top and pick one (“aerobic capacity”, “fractional utilization”, ,etc.). Ask yourself, how do I move the needle on one of these things. How about another. There will be overlap (e.g. endurance and fat utilization). At no point do you say: “I wonder if 80% or 90% or 50% of my training time should be dedicated to this?” “Wonder what that means for my intensity distribution?”

It doesn’t matter (google “sweetspot vs polarized kayfabe”). I spend 100% of my training time trying to take 10-12hrs to improve endurance, fat oxidation, and fractional utilization.

Welcome to the party.


Start by reading the HighNorth articles, this link should take you to the first one from January 2020:

Read them all. I’ve found these to be among the best blog posts available. They are easy to read and with references.

Go there now and read :wink:

Great information and explained in simple language, right?

Back to your comment - there is no ‘best’ training approach. Best is individual although there are some broad generalization you can make. For example on 6-8 hours/week I’ve achieved better overall fitness gains by doing 60-80% at endurance, versus TR’s more threshold heavy approach, but that wouldn’t be true for everyone.

The Scientific Triathlon podcast also has some great info, each week he interviews a coach or exercise physiologist. Its up to you to connect the dots.

What an awesome response and breakdown. I will check out all those resources, I appreciate it! I should probably always remember if someone feels like they have the most rock solid answer and approach ever to training without any skepticism to opposing views, they are probably trying to sell me something. Haha!

Agree with @WindWarrior, High North articles are a great place to start.

I’ll add just one more because I think it’s almost universally appreciated here on the forum (“almost” because it is still the internet, nothing can be completely and totally universally anything) LOL

^^ Like reading a good book ^^

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Another good one that actually cites papers is Cycling Podcasts | SEMIPRO Cycling
Their recent deep dive into CP was especially enlightening

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The grey area is the plan around those two ideas.

I think most coaches know that the ultimate answer is both. Lots and lots of low intensity during base season, add in a little bit of threshold* during build, and top it off with some SIT and/or a short VO2max block depending on the athlete’s needs. And all the while, maintaining the aerobic system with the low intensity rides. You’ve ended up pyramidal and got the best of both worlds.

*Sweet spot is just another word for high tempo or low threshold. Threshold has been well studied.

Nils ver der Poel’s training diary on how he won two gold medals and broke world records is instructive:

What did he do?

Super low intensity “Aerobic” base season. He’s riding at under 60% of his FTP most of the time, day after day.

Then he moves into “Threshold” season - a crazy 90-100 minutes a day of Threshold training @ 90% of his FTP. (aka sweet spot). Then he goes into his “Specifik” phase where he skates lap intervals at race pace (never slower).

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I’m not so sure if that is actually the consensus, at least with regards to some coach’s opinions for time crunched athletes, and where most of grey area is.

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I meant as an ideal. For time crunched, I’ve heard many coaches suggest some sweet spot.


sure I think we are on the same page, but in terms of this study the quantity of “some” can alter the outcome

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I think if I was starting in your field, I’d try to do something in the same area as Inigo San Millan. Not only does he work with athletes, but his work has potentially broader applicability to societal health (eg diabetes, cancer)

Great podcast here. We’ll worth a listen.

What stage are you at? I want to help you. If I design a study, I will use a website that helps with writing, like https://edubirdie.com/edit-my-paper, because it will be much faster and easily achievable. They can help with editing my paper. I will do all work, and in the end, Edubirdie can edit what is not correct, and you will have a perfect dissertation. If you still haven’t finished what you started, I recommend trying this service.

Great topic - I think the Uphill Athlete podcast and blog is probably the best source out there.

And the idea sweet spot and othe types of training improve fat utilization can actually be tested by an Aerobic Efficiency Test (AeT), the basis of which is finding the heart rate which allows for a 5% drop in power over an hour or the power level that results in a 5% increase in heart rate over an hour (or by utilizing a lactate meter).

Almost everyone who trains in the ‘middle/No Go’ zone (per Polarized methods) has an Aerobic Threshold at 70% of LT2, or 30 min max HR - the exceptions being those with high aerobic activities outside of training (delivery drivers, farm workers, janitors, etc). The goal of polarized training is to raise the AeT to 90% to 93% of LT2.

I sincerely doubt that test is doing what you stated.


Most of the work in his aerobic base season was done at 240-280 watts. And that does not feel like super low intensity after 5 hours.

Example week during the Aerobic season
Mon 7h biking at 260W
Tue 6h biking 250W
Wed 2h x-country skiing + 4h biking at 250W
Thu 7h biking at 265W
Fr 6h biking at 240W
Sat Resting
Sun Resting

With an FTP around 400 in the aerobic season, that means he’s working at 60-70% continuously, not UNDER 60%.

It was only during his build phase where he’d drop his endurance intensity to 220 or so (sub 60%), to be able to complete the absurd threshold intervals he was doing.