Ok, fair enough.

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Here's my take on the matter, and I'll start with a quote from an old (CR ?) thread in a post by "DavidD", who was quite familiar with Maffetone's results and methods:

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"This test measures respiratory quotient (as we’ve discussed here many times), which is a measure of fat and sugar utilization. As you slowly increase the running speed on a treadmill, you can see the fat and sugar mixture change, and at some point the RQ suddenly increases. Maffetone chose the corresponding heart rate right before this deflection point as the max aerobic HR."

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The test referred to is a VO2 test, of course.

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Ok, when I had my VO2 test 1 1/2 years ago, it was completely obvious where this deflection point was.  My RQ (aka RER) was almost constant from an HR of about 97 or 98 right up to 117 or so, and by 119 it was ramping up essentially linearly pretty much all the way up to my AT (anaerobic threshold.)  This is also very obvious from my "fat calories / hour" graph, which had a magilla of a peak (the Matterhorn ?) right at 117.  So according to the above origin of how the max aerobic HR would be chosen, my "MAF" determined by the VO2 test would be 117.

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Going to the definition of the 180 formula, as given by Maffetone (180- , with categories a,b,c,d and possible adjustments for age > 65 for those in c or d) my "formula MAF" at the time would have been an HR of 100.

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So... "formula MAF" = 100, "VO2 test MAF" = 117.  Does that make me a card-carrying member?

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Oh, BTW, at HR = 117 my RQ was 0.76, meaning that at this VO2 MAF I'm burning 80% fats and 20% carbs.

Thanks for posting that, Gino. I think you are an example of what both Mark Allen and Dr. Phil say about people over 60. That an adjustment of as much as ten beats might be needed. Though one has to be careful. For someone 70 years old, that would give a range of 100-125 bpm (the usual adjustment range would be 100-115). You fall within that. If someone doesn't have access to an RQ test, then someone your age could take the 180-age plus 5-10 and see if the MAF tests improve. The medication adjustment of ten beats sometimes is necessary and sometimes not. I'm not sure if you are on a medication and that's why you were saying your calculation was 100 beats. Your RQ test shows it is not a factor for you.

Again, thanks.

--Jimmy

p.s. My MAF is at .81 (66% fat, 34% sugar)

 

anyway so then MAF is not the point of 50%/50%?

No. The MAF point varies, but is below the 50%/50% HR.

--Jimmy

 

ok. one confusion is cleared then it was said many times that it is 50%/50% or RQ 0.85 (for example I started reading the old CR forum links you gave in this forum recently and it was said there a lot too)

It's been a long time since I read through those threads from long ago, but I do remember some people

thinking the MAF was the 50/50% point. Dr. Phil never went too much into it in Training For Endurance and the books beyond (which most of us were reading). He did include a little and Mike Pigg's RQ chart in Training For Endurance. Personally, I didn't fully understand the RQ aspect of MAF training until after I migrated to Running Ahead. I understood finally when I read this.

--Jimmy