If you wake up during the middle of the night and want to see how long you have been asleep and the sleep stages, there is no way to view the metrics for this current sleep cycle without telling the watch that you are waking up.
If you tell the watch that you are waking up, then it ends your sleep night in the middle of the night. Not good.
If you go back to sleep after telling the watch you have awaken, the 1st set of sleep stats are overwritten and lost.
Also not good.
Please inform me if there is a way to view current night's sleep metrics prior to "waking up".