Age: 63
Sex: Male
Diet: Some form of low-carb for decades, not specifically for athletic performance but because I feel better eating that way. For the four weeks prior to the test my daily dietary intake averaged: 3042 kcal, 131g protein, 16g CHO, 274g fat. In percentage terms 18% of calories were from protein and 80% from fat.
Goal: Thru-hike the Appalachian Trail April 2021
Background: About three months ago I started reading Maffetone, thinking he would be helpful for my brother who just finished his first marathon. Then a little light bulb went off and I thought, maybe I am an endurance athlete too because I do things like backpack for two weeks on the Long Trail in Vermont (link takes you to a shout-out to Uphill Athlete from the holder of a new FKT.

So, about two months ago, I decided to follow Maffetone. I stopped all strength training and tried my best to always keep my HR below 108 bpm (180 minus age minus 10 for gout medication).

The biggest problem I had was that I was waking with baby steps and stopping uphill and then running downhill on rocky, wet, and muddy trails. For someone like me, with a problematic left knee, I knew this was not smart. But Maffetone stressed the importance of staying within 97-107 bpm, so I would speed up on descents.

About one month into Maffetone, someone told me to look into Uphill Athlete, so I read TFTNA AND TFTUA, and it was if the scales fell from my eyes and a whole new world opened up to me. But before I could develop an Uphill Athlete plan, while I was still doing the Maffetone Method, I messed up my knee going too fast downhill on a rocky trail, trying to keep my HR in range.

About 7 or 8 months ago, I reached a HR of 178 on an elliptical machine (I think I got that high with my mouth closed the entire time). So, I assume that that is close to my HRmax. it should be noted that for almost two years I have only done nose-breathing when training. The only time I have done mouth-breathing is when hiking with others going fast on ascents or, two days ago, when I did my metabolic efficiency test.

My Metabolic Efficiency test operator was certified by Bob Seebohar.

I am attaching the Crossover and Fatmax reports.

My results seem similar to those discussed by UphillAthlete.com member allisongillespie here.

If you look at my reports, my MEP crossover point is rather high relative to my capacity yet I think it is occurring at a rather low level of performance: 18:10 min/mile at 15% incline and 15:23 at 11%. That would suggest ADS to me.

I have not yet done an AnT test and have no idea what speed and incline to start with on a treadmill. I doubt I could maintain 164-167–my supposed MEP–for half an hour, but I haven’t tried.

But, to get started, I am not that concerned for now with my AnT. What I would like help with is understanding where the top of Z2 is. Fatmax is 145 bpm but even that seems high to me, especially since it would be laughable to consider me an elite athlete. (I regret not taking a photo of the computer monitor when the test was done, since the tech didn’t know how to export the raw data that I asked for. I eyeballed the fat g/minute column and my highest momentary reading was 0.92. I was really hoping to hit 1.0, but what really counts for me is performance on the trail, not my lab values.)

I walked about 15 minutes before I entered the metabolic testing facility. I then had a 15-minute warm-up at 0% and 18:10 min/mile, with subsequent 5-minute stages. The test occurred around 7:15 am, I was fasted. I did not exercise the day prior to the test, other than a couple of “stir the pot” reps on a swiss ball around 7 am, before I remembered that all exercise was strictly verboten.

To reiterate, do these tests give me sufficient information to determine my AeT, and, if so, at what HR is my AeT?

(Note: I do not have a lactate meter but did take the following readings:
Blood glucose: 90 mg/dl pretest, 139 mg/dl posttest
Beta-hydroxybutryrate (ketones) 1.1 mmol/L, 0.8
Uric acid 4.3 mmol/L, 14.8)