why sets across?

[JPostSam]

hi, rip. thanks for making yourself available here.

i have a question about sets across, and it's basically this: why?

you're critical of pyramiding because, as you say, it wears you out before you can get your work in. in that case, if you're doing 3 sets of an exercise with the same weight and for the same number of reps, aren't those first two sets just like really heavy warm-up sets? wouldn't you be better off doing each set as heavy as you safely can?

for example, if you're doing three sets of 5 reps with 175 pounds, as in the bench press example from the programming chapter of starting strength (just got it -- thanks for a great book!), doesn't that mean that you really could do about 190 for 5, then 180 for 5, then 170 for 5? (or something close to that?) and if so, wouldn't that be better than 3 sets of 5 at 175? it would certainly mean more power output, especially at higher weights...

i know i'm opening myself up to the usual "just do the program!" or some other kind of reponse that points out that i don't know what i'm talking about. but i'm not trying to sound like a jerk. i really am interested in learning about what makes one way better than another.

thanks in advance.

[Mark Rippetoe]

Experience has proven that the 3 x 5 works for novices and that 5 x 5 works for more advanced lifters. The reasoning is as follows: there is a weight you can train with for 5 reps that allows all the sets across to be done. This weight is light enough that the first sets can be done with good form and the last set to be done with acceptable form. This weight can be increased in a linear fashion, thus driving the adaptation upward in a linear fashion. On the other hand, descending sets would start with a weight at which the form was merely acceptable and the intensity was maximum, thus making all the subsequent sets a max effort due to the fatigue and the form increasingly bad. Bad form form due to fatigue for squats usually means a lack of depth. Therefore, descending sets generally equals sloppy form, less than full ROM, and a very quick halt to progress.

[JPostSam]

got it.

thanks!