Using the same weights for the same number of reps does absolutely nothing to force your body to adapt. (musclegainingsecrets.com)
Won't it just get so easy to do a given exercise, over time, that doing a low number of reps doesn't do anything for you at all? (bodyweightcoach.com)
Decrease the weight by 20 lbs and perform 4 reps and keep removing 20 lbs on each set and perform the same number of reps you did while coming up the pyramid. (fitnessandpower.com)