You can’t avoid it all together lest you want to just outright die. mTOR gets turned on during significant caloric surplus from training. So if you train and eat protein, your mTOR signalling gets turned on. It’s responsible for cellular growth. That means it’s also connected to things like cancer and aging.
You want to turn it on selectively, i.e. during training and then have times where caloric intake is very low, or do some fasts.
This is why I tell guys at 50+ to stop worrying about accumulating muscle mass. Dude, you’re past that. Whatever you can build, is just going to accelerate the aging process and being in a caloric surplus at 50 years old plus? Come on, man. You’re supposed to be past that shit.
Metabolic resistance is a real thing after 40. There’s a myriad of reasons why it becomes harder to not only hold on to muscle over 40 but building new tissue after 40 is incredibly difficult. Especially if you’ve been training for any real length of time.
Worry about getting in awesome shape and putting health and wellness first.