I agree. I can do it maybe 30 minutes and I need to do it before the meal for that day so that I'll not crave or feel too much hungry.I think no one on OMAD can work out for more than an hour. I personally can't. It's very tiring. I also make sure I drink a lot of water while working out. This is very important! I think we're very weak when on OMAD and so one should take this into consideration. You can't have your normal workout routine while on OMAD.