fitness, diet and energy levels.

[astronoth]

If your fit nothing should be a problem for you but if your tubby hauling that large stone aint gonna be that sunday brunch you had twice in one day last sunday.  But if you eat an energy meal comlosed of carbs and sugar along with some coffee why even the largest of objects could be moved quickly and easy. 
But sleep is to energy what food is to hunger.  If your daily energy.maximum between sleep intervals is only suffering say sitting a bench going "ummmm did the antimatter space probe thingy go in the uranus conceivaltor??" than your probaly not expending much max energy levels for days.

If they could get sore parts temporarily thatd be great at a cost of no not mental break!!!   But of productivity.  Also tylenol/painpills.