Q: Is it true that more experienced lifters need fewer reps for hypertrophy (size gains)? Does training age really make a difference?
A: Yes. What happens is that most hypertrophy gains usually occur between 70 and 85% of max. (That's a gross overgeneralization, but we can use it as a rule of thumb.) Now, an untrained individual will do between 7 and 12 reps in that range, but for an advanced lifter that's only 4-6 reps. If you're experienced and neurologically efficient, the amount of reps you can do at a given percentage of max actually goes down.
Now, there's some evidence in the literature contrary to that, but the majority of it agrees that the number of reps you can perform at a given percentage of max diminishes with training experience, particularly if the athlete has been training properly. This is especially true if levels of maximal strength have increased a lot, as in double bodyweight raw bench press.
How many years of training experience are we talking about? Approximately three years. Again, that's assuming you've been training correctly.
Very gifted lifters can hypertrophy at 2-3 reps, but they must do more sets; on the order of about 10 or so. So an inexperienced guy may put on muscle at 3 sets of 10, but then three years down the road he can put on muscle at 10 sets of 3.
