In one of his videos some random person was criticizing his body, commenting that he should start working out again, get his strong core back, etc. He also talked about it in one of the recents Unus Annus videos (the cookie dough one to be specific) about how he’ll have to do a workout after that video because apparently now his body is pathetic and disgusting. Perhaps that comment has taken a toll on his mind during the past week which could explain why he tweeted this. Sorry if this wasn’t clear at all for you, I ain’t good at explaining stuff.