Sleep is just as important to physical health as going for a jog is. This serves the same purpose as a fitness tracker, just that the activity is sleep. Getting off the couch and going to bed earlier and more consistently can help you lose weight by boosting your metabolism, give you more energy for the day, improve cognitive ability, and reduce your susceptibility to disease.
Right. But that's where my confusion comes in. You don't really need a gadget under your sheet to tell you to not get 4 hours of sleep a night. For something specific like sleep apnea I can somewhat see the usefulness, although I'm not sure I'd trust something like this over the more in-depth equipment used in a sleep study.
But for the general public, I just don't get it.