Stupid question?

I've recently read that I'd benefit from a 5x5 routine of various compound exercises. (the objective is to achieve muscle growth)

The weight should be sufficiently heavy so I can only just manage the 5th rep. In order to progress when all 5 sets can be completed then up the weight. That can be interpreted as that when I start the routine I won't complete a total of 25 reps for a given exercise.


Does this mean that I shouldn't be using the same weight on all sets? If not, does it mean that each set the weight will be getting lighter or heavier or doesn't it make any difference?

i find if my progress slows on something i.e. bench .... if i do a 5x5 routine on that for a week with a slightly heavier weight, come the next week ive increased by a couple of pounds