Not sure about that but there was a study during WWII – in Britain, I believe – that showed a negative correlation between hours/productivity. Essentially, once you push workers past 40hrs week, they don’t really produce any more than they would if their hours were capped. Exhaustion, hunger, thirst, physical accidents, mistakes, all adds up across a workforce so the returns diminish quite quickly.
Or breakroom, by the sound of it.