If I understand BBM correctly, increased strength and size is directly related to increased volume, so, as long as volume, whether that be in sets (adding additional sets to an exercise/routine as needed), reps (adding reps to an exercise before increasing the weight (4 sets of 4 to 6 reps; start with 4 reps, and, when I can do all sets for 6 reps, increase the weight and start the process over)), or increased weight over time, I should continue to make progress.
If volume is all that matters, is it possible to stick to only one basic workout template as long as I consistently manipulate sets, reps, and weight? Or should my template change periodically, as in exercise selection or loading?
Volume at the appropriate intensity* is the biggest predictor of hypertrophy and strength outcomes
Some additional programming variables like exercise selection, rep range, rest periods, etc. influence both intensity and volume
*appropriate intensity is fuzzy, but the general rules are:
For strength improvements, a person needs regular exposure to similar intensities to how they will be tested
For hypertrophy improvements, nearly any intensity will work if you do enough reps (or enough weight) to make the effort hard (RPE 6-7 at a minimum)
We wouldn’t say that volume is all that matters and there are elements of programming you would want to change at different times depending on what goal(s) you’re chasing, mainly exercise selections and intensity ranges, which will change the appropriate volume level.