[Blitzzz (RIP)]

Most of you know that their are thriid types of muscle fibers in each bundle.Two phasic and one tonic. all of these are prioritized from birth to present . Your brain calculates all of your movement in the line of gravity and is able to recruit the fibers needed to preform desired or required muscle contractions to acomplish given tasks
The fiber are prioritized primary secondary and tertiary. The primary and secondary work pretty much the same. the difference between lifting a styrofoam cup and a 5# bag of sugar is in the instantanous recruitment of the necessary fibers to accomplish the work. Thusly the primary and secondary get the bulk of what you do. The tertiarys will assist some but "quit" when the primaries quit. The only way to exercise the tertiary to strengthen is to "keep it engaged" when working it. Under normal and greater work loads the pprimary and secondary get stronger and fatigue with all other systems used. The tertiarys quit and are never worked to potential.
Blitzing is done with little enough weight to fatigue through reps, the primary and secondary, and allow the tertiarys to remain engaged, and thus strengthen the tertiarys like no other system.
Look at it like this., a third of all your muscle bundles is working at around a third of it's potential. Blitzing is the only way to get to and strengthen it.
I learned of tertiary prioritized fiber in PT school and have found very little references to to as such since. The fact that this systen strengthens so greatly over all other systems is a good indicator of their existance. Nothing else will give these strength gains. Blitzzz