One of the most obvious reasons to wear a smartwatch to bed is the sleep tracking capabilities. Some brands and models may offer slightly different features, but you can expect most of them to at least keep track of your sleeping patterns.
Smartwatch sleep tracking is no substitute for official medical sleep testing and equipment, but it can be a useful tool all the same. Charting out your patterns can make it easier to figure out when you get your best rest, determine what factors may help or hinder (for example, was it raining on the night you slept more soundly than usual), and so on. Think of it as extra data points you can show to your doctor if you ever need to talk to them about how you’ve been sleeping.
You can also use your smartwatch to set up sleep schedules (times for heading off to bed, waking up, or both). Set a reminder for when you should go to bed so you don’t accidentally stay up too late. Choose a time you want to wake up, and the watch will do its thing in the morning. Or, ideally, combine sleep reminders and wake-up alarms with your sleep tracking info to encourage yourself to get the amount and kind of shut-eye your body needs to function more effectively.