Do Cyclists Dream Of Biphasic Sleep?

Lately I have been wearing my Garmin watch for more than just walks around the neighborhood. I’m trying to get deeper into all of the health metrics that it can provide, including sleep. I started to look into these numbers more than three years ago, but I didn’t stay consistent. Maybe there isn’t that much to see and I will give up on it again. Right now, though, it’s kind of interesting.

I’m a biphasic sleeper: on a typical day, I sleep in two distinct periods instead of getting all of my sleep in one block. It’s not uncommon for me to be mentally fried at the end of an overnight shift, so I usually go to bed shortly after I’m done with work. What follows is something like this:

And that’s clearly not enough total sleep, especially because there’s so little deep sleep. (The heart rate bottoming out at 39 beats per minute is pretty cool though!) I’m always up again by early afternoon, when I have a very active period that might include exercise, grocery shopping, yard chores … anything you might do between the end of your workday and your bedtime. But after dinner—and especially in winter, when it’s already dark outside—my energy drops and I return to bed for as much sleep as I can get before my next overnight shift:

Add those up and it’s about seven hours of sleep in a typical day. A lot of people would take that if they could get it, but how many of them would still consider it a good deal if they had to get it in two blocks instead of one?