Bryan Johnson, who has become known as the man who will try anything to stay young, has revealed some unexpected NSFW information about himself - and says he's attempting to be comparable to an 18-year-old. Johnson, 45, pulled out a device while on Steven Bartlett's podcast, and explained by how measuring his night time erections, he can get a good indication of his health. He said that he's currently on two hours 12 minutes per night, however, his goal is to get to the standard of an 18-year-old, which is three hours and 30 minutes. Sign up to our free Indy100 weekly newsletter