Yeah, it will double the load so to speak. So if you wanted to train corners for 8 sessions, it would only take 4 days to do the 8 sessions instead of 8 days.
I think most guys for 'morale building' use 'rehabilitation' at night to avoid players going awol and 'nice rest' during the day for players to recoup their fitness.
Agadorsparticus has helped me with a few questions, best advice is to use the strategy tips section of the forum.