My body is still reacting to my lack of sleep on Monday night. I woke up after 5 hours sleep and didn't go back to sleep. I stayed in bed for the next two hours to help my body adjust. My wake up HR is still 50, and my body feels tired., so I'm taking another rest day today. I went to bed last night at a reasonable time, but my body needs several days to return to its normal sleep patterns. I normally wouldn't go into this much detail about my sleep patterns, but since this is a tutorial log, I thought it would be educational to illustrate how stress increases with lack of sleep.