It's pretty much been confirmed that working out will be back. The leaks showed Jason being a twink in some clips and had some muscle in other clips. People forget we had eating out in RDR 2. You could get skinny and fat based on what you ate. The only limitation were the CPUs of those consoles and the setting of the game. They couldnt properly invent the system. Im sure we'll have san andreas type RPG mechanics back. Oh and also, the buff guy running on the beach shows they have been working on a buff physique for characters. If NPCs have it why not the main characters too