Here’s my two cents on this mess. This argument of recruiting all the various fiber types can get nasty depending on many factors such as, % of 1RM for each set, speed of movement etc…The Type I’s are recruited first for muscle tensions up to about 25% of 1RM, the Type IIA are recruited next and the Type IIB last. Since fibers are recruited as needed, provided intensity is high enough and the set is taken far enough you can recruit all the various muscle fibers in one set (not meant to be support for HIT). Now I’m not recommending this is what you do, I’m just saying that if your intensity is appropriate you will activate most of the muscle fibers. Don’t forget speed of movement, both a small load accelerated rapidly and a heavy load accelerated slowly involve the Fast Twitch fibers. Just to add more confusion to the mess here is a worth wild quote form Mel Siff. “Research reveals that this high intensity is not necessarily dependant on the use of 1RM but the degree to which the relevant muscle fibers are recruited during the effort. In this respect, the terms fast twitch and slow twitch do not necessarily mean that fast movements recruit FT fibers and slow movements recruit ST fibers. To analyze the involvement of different fiber types, it is vital to determine the force that needs to be produced.” So keep in mind Newton’s 2nd Law of Motion, Force is equal to Mass x Acceleration…low forces will involve ST and high forces FT. Within F=MxA you have factors that also influence force production like stretch reflex, length tension relationship, angle of pennation, prior DOMS, and muscle cross-sectional area….it can get complicated and ridiculous.
Now that I’ve probably confused JK, here is my best advice. I wouldn’t worry too much about recruiting Type I’s anyway, they don’t hold much potential for size or strength, and provided you are lifting heavy enough with varying accelerations you’re going to take care of the other fibers. Just stick with what you’re doing for a bit and see what kinda results you get. Simply, if it works for you do it, if it doesn’t dump it. My prior rambling was meant to show just how deep this argument could get, and also how meaningless it can be. Just work hard and make sure your reps and sets are relevant to your goals and you’ll do fine…Ahhhh my mind feels stimulated.
To Marc: Drop me a line sometime, I still have my old school e-mail address from the Edwards Hall days.