Ok, maybe I was soooo tired during chemo that I couldn't drool without falling asleep. But many doctors encourage some healthy activity too. Some studies show that, on average, chemotherapy patients who incorporate exercise into their lives have shorter hospital stays, experience a lesser decline in physical functioning, report significantly less fatigue and emotional distress, and enjoy a higher quality of life during treatment. Of course you should ask your doctor if this is ok for you.
Some references: