In the powerbuilding template, we use the calculator to estimate the weight we do for each of the 3 sets: RPE 7, 8, and 9. Obviously, an RPE 9 weight will be heavier than an RPE 7 weight, based on the calculation. My understanding is that we are able to raise weight each set for a higher RPE since we should be recovering adequately (3-5 minutes) between each set.
Would the same effect be achieved by taking less rest (1-2 min) and keeping the same weight on the bar? The subsequent sets should be higher on the RPE scale, even with the same weight (given less recovery between sets).
While it’s fine to have ballpark targets in mind when going into a session, we don’t tend to pre-calculate absolute working loads (as discussed here e1RM increments for the Squat and the Deadlift - Training Q/A with Drs. Feigenbaum & Baraki - Barbell Medicine Forum ).
Taking less rest and keeping the same weight would likely increase the effort of subsequent sets, yes (this is the idea with myo-reps, for example, whereby we use restricted rest periods to generate more fatigue and get high motor unit recruitment at relatively low loads). I would not expect this to generate identical strength outcomes to handling heavier loads, however.