Is it better to lift heavy then go lighter or the other way around... an example would be lifting...i don't know something like 100 lbs X 12 then 90 X 12 or is it better to go the other way, start light to get warmed up then go heavier? The trainer said to start heavy but I'm not sure about that guy...(and the weights and reps aren't whats actually being done, I am just using that as a general example)