On the other hand, machines
allow you to focus more on the effort and less on the mechanics of the movement, and this can be useful for the end of your workout, when
accumulated fatigue makes balancing weights over your head very difficult.
The reason why we work in the 60 - 80 % range so much is because working in this rep range
allows us to prescribe higher volume to our athletes without
accumulating a ton of central nervous system
fatigue.