Originally Posted by DannoXYZ
Yeah, "intervals" at LT or below aren't really "intervals". They're tempo workouts for the aerobic system. Real intervals are anaerobic above LT and taxes your muscular system. Increasing muscular efficiency allows you to generate more power at LT and more power for any given oxygen-consumption. If you didn't hit 100% MHR by the end of the interval, you didn't push hard enough.
Ahhh, maybe we're using different definitions? First off they are "real" intervals whether they are at 88%, 95%, or 100% of MHR or FTP, at least in my world.
Second, hitting 100% of MHR for an FTP interval would no longer make it an FTP interval, instead I'd be doing anaerobic work or AC intervals, and couldn't possibly hold MHR or Anaerobic power for 20 minutes. Insofar as "pushing hard enough is concerned" per my other post (in response to NoRacer's comments) IMO and others opinions you don't need to be "redlining" to see training adaptation in various energy systems.
gene r