If doing martial arts and weights for years, what would happen if they gave it up for 18 months?

You think someone on SW is gonna have a clue about that? Ask about eating a whole package of pork rinds or marrying your cousin.

Martial arts when you are well-trained.As like riding a bike , you never forget. Body building is a little different because yes you will gradually get out of shape but you can fix that again

They're going to ban weight lifting soon because Chinese weights are gathering information.

They'd be slightly depressed I bet

depends on what you spent that time on... if it was eating pints of ice cream that didn't help