So I recently visited the lab on campus at the University of Texas in Austin. It is called the Fitness Institute of Texas.it was very reasonable and they were very professional. My aet or lt1 was at 126 bpm. This was where my lactate crossed 2mMol/l . My lt2 or ant crossed 4mMol/l at 152 bpm. My max hr is 169. I have ads and plan on using the next 6 months to build aerobic capacity. The good news is that working out in zone 2 is pretty easy and will allow me to build volume rapidly. The bad news is that at 125 bpm I am basically at a brisk walk. Should I go 100 % in zone 2 for the next several months or would an 80/20 split between aerobic/anaerobic make more sense ? Any thoughts? Also I guess I’ve always trained too hard in the past. I’m going on faith that several months in zone 2 will make a strong positive change in my aerobic capacity. I expect to be able to go longer faster and still mostly metabolize fat as an energy source several months in the future. Is this reasonable ?