MAF running questions


Hi everyone!

I’m wondering some stuff about MAF training. Basically, being 41, I should stay under 139bpm.

Last March, I had a vo2max test done on a treadmill, with analysis of my lipid/glucose burning, etc etc, and according to the physio/trainer giving me the test, my zone 2 (aerobic) zone is 128 to 152bpm, with a max HR of 200 (very far from the 220 - age). Would that skew the MAF zone at all? I find that since I went keto (about 1 month strict in right now), my HR while running is like 15 bpm higher for the same pace.

example, my comfortable 5k time pre keto, would be 28-30 minutes. 5k time in low hr, 37-40 minutes. 5k time Keto, if I try to keep the 152 limit, 43-45 minutes. If I try to stay under 139, then it’s like 50 minutes.

Should I adjust the MAF upper limit? I’ve been running consistently for 6 years now, 1000-1200km a year, and yes I’ve had a few injuries, so im not supposed to use the + 10 allotment of the formula…

What do you guys/gals think?

(Michael - When reality fails to meet expectations, the problem is not reality.) #2

(Edith) #3

My resting HR has not increased on keto, but I found my running times were not improving when I used the MAF calculation. I had to up my numbers by about 10 BPM.

There’s been discussions of this on other threads. You may want to do a search.