Hi, I scanned the past posts to see if I could find any questions similar to mine. I apologize if my question has already been answered.
I live in central Idaho and my goal is to be able to hike up steep mountains easier and faster than my hiking buddies. I am 58-years old and not an athlete in training, I am a backcountry skier, hiker, and hunter. I spent the past 2+years “training” (hiking) in Zones 1 and 2 to cure ADS. My AeT is now 8 to 10% of my AnT. Lately, I started to slowly introduce Z3 intervals and now I am at a point where I started to do occasional Z4 intervals (once a week to once every two weeks).
For the Z4 intervals, I hike ambitiously up a 30% hill. The summit is only about 4700’ feet in elevation. I noticed that I cannot get to my VO2 max HR of 172, no matter how hard I try. The highest I can get to is around 166. Even though I cannot sustain the 166 HR for very long it still feels like l like I am not at the maximum “fatigue” in my breath and muscles. I should add that getting to 172 was not an issue before I started concentrating on Z1 and Z2 hikes a few years ago.
My question is, is there a possibility that my maximum HR is limited by weakness in my fast-twitch fibers in my legs…kind of like not all my FT fibers are kicking in? If so, I assume that over time, hiking in Z4 will eventually build up my limited FT fibers? I have not been doing any weighted ME hikes. Maybe doing weighted ME once a week is recommended for my situation? Thank you!