The text says 24-60 hours, but then in the table where they talk about the other studies being considered, a lot of them did 48 hour minimum and as much as 96 hours for some. When I saw the headline I was excited because a 16-18 hour fast really isn't very hard for most people, but 48 hours sounds a little rough. I guess if it's just a one-off event while you're doing chemo it's not that bad, but I'm not about to fast 48 hours once a week for the rest of my life.