Some of you may be thinking I've just done a 100% reversal in my opinions. I'm searching for the optimum exercise that can help me. This is worth sharing and it helps reinforce my decision going from static contraction and start using the big 5 could be a good decision.
This link is a summary of a study done by Dr. Carpinelli and Dr. Winnett.
Here is a good quote by the author:
Body by Science, an important book by Doug McGuff, MD, and John Little (2009), explains the problem: “If you use a weight that is too light….you will recruit the slow-twitch fibers into service, but because they fatigue so slowly, by the time you have started to recruit the intermediate fibers, some of the same slow-twitch motor units will have started to recover. They will then recycle back into the contraction process, thus preventing you from ever engaging the higher-order muscle fibers.”
McGuff and Little say the problem is similar with a weight that allows only one or two reps: All motor units (slow and fast) are activated, but the fast-twitch units fatigue so fast that “the set will terminate before you’ve had the opportunity to thoroughly involve and stimulate the bulk of your slow- and intermediate-twitch fibers.”
Dr. Carpinelli might say it’s supposition, but McGuff and Little argue that a moderately heavy weight allows you recruit the full range of motor units, “but not so quickly that only the fast-twitch fibers receive the bulk of the stimulation, and not so slowly that the slow- and/or intermediate-twitch motor units can recover and you end up cycling through the same lower-order motor units again.”
Little mentions on his website that:
"To build muscle it must be trained within its anaerobic pathways (up to 70 seconds); any training beyond this point dilutes the potency of the training stimulus and could cost you muscle."