how to hypertrophy only certain muscles?

[khrazz]

how to hypertrophy only certain muscles?

Hello this is
  the first time I post

I have trained for 3 years and I have developed some muscle mass in my back and chest, with which I am already satisfied, but my arms and legs have been left behind.
I would like some advice on how to increase only my arms and legs, while I only keep the rest of the muscles, I know that this could be impossible, but I do not expect anything magical just some tips that could help in the ranks of an natty brah, even if my back or chest goes down in volume

Well, for one as you said you cant hypertrophy certain muscles without the others either de-training or getting worked out themselves.

Here is what you can do. You can either increase the volume per workout for those muscles you feel like they need to catch up, or the frequency of their training, or both!

So for legs, you can do
Squats, deadlifts (any variation of those) and at the end of your workout, do some isolation like leg curls. You can also add more exercise variation in a training day, like for example, doing 3 heavy squat sets, followed by 3set medium weight squat, followed by 2 sets of front squat. That is a LOT of volume for your legs.

As for arms, you dont specify, biceups? triceups? I assume its most likely your biceups. Well the biceups get a ton of workload by doing weighted pull-ups/chin-ups, and heavy barbell rows. After that, you can add more volume by doing cable row/cable lat pull down. Lastly you can add barbel curl to finish off your workout. If you want to add dumbells, you need to remember that the workload in dumbells is little, so you need to do a lot of reps (10-12 or even 15) .

In my opinion, you need to work your entire body, and just do some "finishing" exercises in the end to add more volume to the specific muscles you want. Best of luck