The 72-year-old Sylvester Stallone might have hung up his boxing gloves in the Rocky/Creed movies, but there's one legacy character of his that isn't going down so easily: John Rambo. Production on Rambo 5 (which may or not still be called Rambo: Last Blood) is set to begin soon and Sly is getting himself into what looks like ridiculous shape. He teased us with what he's going through with an Instagram post in which he was furiously grunting and groaning in a gym while wearing a Rambo mugshot t-shirt to Guns N' Roses' Welcome To The Jungle. As he comes to what appears to be a weights-induced climax he sits up and giggles "Welcome to the jungle."