Comment by hunter-gatherer

I think what OP is specifically refering to is the intensity level that varies among individuals. I suspect that oft times when people train with a low weight/high rep scheme, they accidenrly let their intensity levels slip. I suspect that for most people, especially newer lifters, doing a high weight/low rep scheme makes keeping the workout for intense because it is easier to focus on being intense for a short time. Just a thought....