I'd love to pose a few questions regarding the volume/intensity of the subT workouts:
(1) I've read of folks pacing their workouts to hit their LTHR at the end of the last rep. I've also read of folks who leave a meaningful buffer, ending 3-5 beats below LTHR. A meaningful choice? In my case, those two approaches lead to paces maybe 15 seconds/mile apart, so rather different. Other than load management, any reason not to go right up to LTHR? Any physiological difference? Slower could allow for more reps vs faster fewer (while adhering to the 20-25% time target) (especially for the 10 min reps)?
(2) I assume that the 20-25% subT time target is about load management and not some physiological balance? Meaning, if you could handle adding more easy miles, your subT% would get diluted - and there would be no problem with that I assume?