I do sometimes and I don't. Usually if I do its a snack, and during an extra treatment (3rd or 4th 30 min vest of the day)
I try and not be passive about the vest. But to be brutally honest it is freaking exhausting- that exhaustion that seeps into every pore of your body, to cough like that every five minutes. It takes energy that I don't always have, or could have used for other things.