Subject: how does the body gain and/or store energy during sleeping

when we go to bed we feel tired, but the next morning were filled with energy, 
but all we did was breathing and sleeping, what happens in the body when we 
sleep regarding to gain more energy. I think were unconscious during sleeping, 
and conscious when were awake, so can we only gain energy from just breathing 
when were sleeping and unconscious? I am very interested in that. thank you 

Re: how does the body gain and/or store energy during sleeping