Nath

I know people that train twice a day 3 days a week. I tried but I found even training different muscle groups in the 2nd session, I didn't have enough energy. I prefer once a day 6 days a week, that way every body part gets hit twice a week and ur fresh for each session. I guess there's no hard and fast rule, whatever floats your boat, 2 15 min sessons might work for some people, seems a little short to me, even if u are only resting say, 30 secs - a minute between sets. Does the 15 mins include warm up/warm down?