Yah, I timed out my sleep cycles and it's about 90 minutes for me. Sometimes Fitbit and similar devices can show people this as well, but it's not always accurate (it was another confirmation for me rather than the primary way I determined the cycle length). And you are correct (and I encourage others to figure their cycle out), if I wake up on the cycle break (for me, 3/4.5/6/7.5/9) I am much less foggy and sleep inertia is reduced than when I wake in the middle of the cycle.
Another way to try to wake at the proper point is an alarm that gradually increases in intensity - you can set it about 30-45 minutes before you have to get up, and if you are already in a wakeful state, you'll hear it when it's low, but at the end it will get loud enough to ensure you get up.
Lastly (and not a shill for Fitbit, it's just the one I use), Fitbit has an alarm feature that will try to detect when you've moved into a light sleep stage and go off then (again, you tell it the latest time you want to wake, and it'll start monitoring 30-45 minutes ahead of that time, and go off when it thinks is optimal).
Long story short, I feel like, while they aren't perfect, we are starting to get some awareness of the importance of sleep cycles and some tools built around that awareness, which is pretty cool.
Another way to try to wake at the proper point is an alarm that gradually increases in intensity - you can set it about 30-45 minutes before you have to get up, and if you are already in a wakeful state, you'll hear it when it's low, but at the end it will get loud enough to ensure you get up.
Lastly (and not a shill for Fitbit, it's just the one I use), Fitbit has an alarm feature that will try to detect when you've moved into a light sleep stage and go off then (again, you tell it the latest time you want to wake, and it'll start monitoring 30-45 minutes ahead of that time, and go off when it thinks is optimal).
Long story short, I feel like, while they aren't perfect, we are starting to get some awareness of the importance of sleep cycles and some tools built around that awareness, which is pretty cool.