I've stopped playing chess as a teenager having reached ~2360. I was national youth champion, a vice-champion, 5th in the world at one point. I played 100+ games every year. Each game could last up to 5-6h. Some games were exhausting, some not. After each game you had to prepare for another one - study your opponent's games, prepare openings and variants. This effort took tool on some and older players were visibly weird, plenty were alcoholics. I used to say that football (soccer) players have bended legs, chess players have bended minds.<p>Anyway, if you want to make chess your profession (you don't need to be a GM to make a living), keep your mind healthy!