Not your typical rock star in terms of substance use. A legendary bootleg from 10/2/75 in Milwaukee, at the long defunct Uptown Theater, involved a bomb threat, as an unusually intoxicated Bruce said while drinking at a bar during the bomb threat break to the bartender "are you loose?" and he continued to make that comment on stage after the show resumed at midnight. The linked article says it this way: "Springsteen and company took the stage, appearing well lubricated, a fact that remains notable to this day, as the temperate Springsteen has never been seen to be drunk onstage at any other time."
The length and energy of his shows was already well established by early in his career. The ability to continue to do that in his 70s is due to his not living the stereotypical rock and roll lifestyle.
His LA set was 3.5 hours long. Incredible.