Male 55, LT1 270w, MLSS 340, CP380 (est), also 4.4wkg. Keep on keeping on, dude, you're doing fine. His HIIT is actually SIT. Where's the evidence for SIT? You'll never hit VO2max in the severe or extreme zone, it's the definiton. There's a whole chunk of training he's ignoring, and no wonder his LT1 is 177w (so he posted on Instagram). Yeah, if you spend hours a day doing threshold work you stand a chance of dangerous left ventricular hypertrophy and afib, but we're not Toni Martin, and not even Toni Martin was Toni Martin. If you're RHR isn't in the mid 30s, I wouldn't worry about it. Seiler and Burnley went head to head on the matter recently, but I haven't gotten ahold of the papers. PA is following Milan, but if you follow his twitter, there's some nonsense there. The only reason I pay attention to him is his work with Brooks. Any, as WhoCares said, 80/20 is pretty good, but that 20 should be threshold, not SIT. I've been looking at DFA alpha / HRV for determining LT1, and that interesting, because you see day to day the same HR is coming in at a different price with the sympathetic system.