I can't be entirely sure what was meant but my sense from talking to people in this area is that statements like that are being made very literally. As in, if y

I can't be entirely sure what was meant but my sense from talking to people in this area is that statements like that are being made very literally. As in, if you do not sleep at all one night, its not like you can sleep an extra 8 hours the next day and be totally restored. The recovery process might involve a couple of days of sleeping an extra 3 hours, just for example. I get the sense exercise and injury are good analogies. If you overexercise, cutting back by the amount you overdid it is too oversimplified; if you stop exercising for a month, you cant just expect to need or suffice with a month's worth later.