Blog post and ex. phys
RnP, I was just reading the recent blog post
Question for you about the statement:
Zones 1 and 2 = Limited Adaptation: If all you do is exercise at Zone 1 and 2, you have entire squads of slowtwitch and fast twitch fibers that are never recruited, never forced to adapt. In other words, you’ll get very, very good at riding and running very slowly!
I believe that the spirit of what you're saying is correct, but the mechanism may be a bit different, if I remember my neuromuscular activation stuff right (it was my Masters' work, but it's been a long time since I used it, and don't know if the science has shifted since then).
I remember that muscle fibers are grouped into Motor Units, which are all activated by the same nerve ending. These motor units are rotated during exercise, to prevent a situation where you had 'tired out' some slow twitch muscles, but had perfectly good ones right next to them which hadn't been used.
Imagine a situation where, during the course of sub-maximal exercise, you're using 80% of your slow twitch fibers. Over the course of your workout, all of your fibers will be utilized for some fraction of the total workout. So all of your muscle fibers get a workout, but it's only 80% of the total time (ie. you worked out for an hour, but each muscle fiber/motor unit only got 48 minutes of work).
IMO, this is the other big advantage of doing work, where you're utilizing as many of those motor units as possible for as much of the workout as possble. OTOH, I may just be a bit off in my memory of how motor unit recruitment works.
Thoughts?
Mike
Comments
Mike,
Sounds very good, interesting, and you're definitely smarter than PnI. Please post your comments to the blog and share them with the rest of the world. Thanks!