With the endurance demanded of me with the quintet music book, I cannot take a day off as it really does diminish my performance level the next day, and it takes me about a week to recover. AND if it involved a gig day (the next day) I would not be able to make it through a 4 hour gig.
I think the classical saying applies:
Miss one day, you know it
Miss two days, the ensemble knows it
Miss three days, everyone knows it