I've had sleep studies (both at home and in a lab, 2 of each iirc). Only one of them determined that I might benefit from a CPAP machine and I was barely above

I've had sleep studies (both at home and in a lab, 2 of each iirc). Only one of them determined that I might benefit from a CPAP machine and I was barely above the criteria that determined such. The others did not indicate any significant sleep issue. By that measure I don't see why the clock hours wouldn't reasonably correspond to the rest I actually get and (presumably) require. Given that I didn't drill down to the study that this article (and other recent articles) are based on, my comment is as much a critique of the journalism as anything else. But by my reading of other studies, 9 hours is in the range of "normal" and this article leaves it in a grey area.