>>124984 there once was some austrian dude on the 4/cyc/ one late evening who did some intervals, some shit like 30 seconds on a few minutes off or so, and it destroyed his heart his heartrate was like a constant 180+ more than an hour after he stopped and he was rage posting from the hospital, as if we destroyed his heart. Which I would have, if I could have of course but he had only himself to blame. Never saw him again, probably dead.