Also cant remember this, but:
I know that training closer to 1RM activates more motor units, but what if you are doing max effort on 20-60% loads? How does it differ from 90% work where you inherently have to do max effort to lift the load?
You pretty much have full recruitment by 75-80% of 1RM or by moving lighter loads as fast as possible, or as fatigue sets on towards the end of a lighter set.
The only difference is the firing rate, twitch, of muscles increase with heavier loads near 1RM.
Also there is theory that the first few reps of 60-70% of 1RM are closer to what happens with heavier loads, where all the fast twitch fibers are present and firing, but soon start to fatigue after a few reps, hence why bar speed slows down.
As opposed to them kicking in with lighter loads near failure.
Which does make sense to me. If the largest, strongest and fastest motor units are still around why is the bar speed decreasing past the first few reps on moderate loads? They are most likely dropped out by then, and the slower more fatigue resistant motor units are the ones still hanging on
