probably a weird question but ive started going to the gym and was wondering if gaining more muscle will make me need to reduce my sens. i am low sens so i do tend to use my arm a lot when aiming and flicking
No AIM effect, but brain boost since you're doing exercise.
It could only affect AIM if you become something like arnold schwarzenegger so it can affect you aim because you won't be able to be flexible with your movements at all.
But doing gym to have a nice body shape = no bad side, only good side.
Faster brain, better reflex, better body, and probably gonna find a better gf.
Only gains.
Go to the GYM.