MAF is Maximum Aerobic Function as determined by Phil Maffetone’s 180 formula. Phil’s traditional 180 formula was developed in the 1970/80’s to easily determine an athlete’s Maximum Aerobic Function. Simplistically, it’s 180 minus your age. So for me it’s 144.

Except, I just re-read the link from above and there are some additional factors. The key one is that I either qualify for Category 2 or Category 4. Category 2 is because I am, according to Phil, overfat… by a long way. Category 4 is because I’ve recently gone through a stressful marriage breakdown. So by that calculation my MAF should be 134 or 129.

So I may have to just suck it up and deal with running slower and walking more often until I’ve lowered my weight and reduced my chronic stress. Given that I’ve seen some improvement between my two MAF tests, and I did my first MAF at approx 146 because I didn’t set the limit on my watch properly, I’ve decided to stick with 144 for now. I’ve also only very recently switched to a carnivore way of eating so I’m still in an adaptation phase. If I see a deterioration in MAF scores, I’ll review.

Month1st Km2nd Km3rd Km4th Km5th KmMAF HR
Feb ’198:529:189:209:149:12146
Mar ’198:338:559:249:27144