Not sure what time it starts as we usually do our own thing in the gym but I seem to recall that it was relatively early (another reason we didn't do it!). Seems to me that I did see them one morning in the sports area on deck (?) - they may have started as early as 7 or 7:30 but it will be in the Navigator. Could have been yoga as well but I don't recall a lot of yoga moves. It looked more like light stretching. If I'm up at that time of the morning on a cruise it's: (a) because I'm going on an early excursion; and/or (b) I'm pouring massive amounts of caffeine into my system. It would be nice to do, but see prior sentence - not likely going to happen on upcoming cruise either.