Are you no longer making progress, are you a hardgainer? Then it might help to train in a different reprange.
WHEN HARDGAINER?
First and foremost: a hardgainer is someone who has training, nutrition and rest in order and who nevertheless achieves little or no progressive overload. See also this article for a correct name of the term hard gainer.
BREAK THROUGH PLATEAU
Depending on your situation, there are a number of strategies you can employ when you hit a plateau. A relatively new one is to change your reprange.
Yes, in principle you can achieve optimal muscle growth in almost any rerp range. But if muscle growth is not forthcoming, it may be wise to choose a different rep range. So for example 15-20 reps instead of 6-12 reps.
RESEARCH
We base this advice on a recent study by Carneiro ao. The researchers compared a group of women who trained with 80% of 1RM with a group training with 30% of 1RM, everything else being equal in their programs. On average, the groups gained a similar amount of muscle. Which once again shows that reprange for muscle growth is not so important.
After 12 weeks, each group switched to the other group: both groups trained for 12 weeks at each intensity. Interestingly, people with a low response to the first intensity tended to respond favorably to switching their rep range, while high responders performed well regardless of the intensity.
This study has major limitations; according to coach Menno Henselmans, she nevertheless adds provisional support to a growing body of literature showing that different individuals can respond differently to a particular style of training. If you don’t respond well to low reps, for example, you can still do well with high reps.
PRACTICE
Don’t just change reprange. First make sure that all training variables, your nutrition and your recovery (rest) are in order. Only change the rep range for the muscle groups that are lagging behind.
FINALLY
The interesting thing about the research is that it shows once again how important customization is for the natural bodybuilder: everyone reacts differently to a specific training protocol.