According to sleep science, humans cycle through several stages of sleep during a sleep period. Depending on the scientific source, they may divide the sleep cycle into four, five, or six sleep cycles. Look how neat the sleep cycle progression is in the hypnogram below. One should typically progress through those stages in 90-120 minutes and then go through the stages three or four times during a sleep period. I think most of us are atypical. In reality, it is not that neat. That is what makes fatigue mitigation an individual experience.
My sleep tracker uses three stages: light, deep, and REM (Rapid Eye Movement). The deep stage is necessary for physical recovery, restoration, and growth. The REM stage is necessary for mental recovery, restoration, and processing of information. Each of us needs an adequate percentage of each stage of sleep in the sleep cycle.
As an experiment of one, my sleep stages for one night are displayed in the column to the right. It does not look like I neatly progressed through the stages, but went back and forth with two interruptions and lots of tossing and turning. It is likely that I was not well rested the next day.
I usually have a larger percentage of light or transitional sleep. There is little benefit in getting frustrated that I do not get a larger percentage of deep and REM sleep. Part of it may have to do with age and health and weight. Part of it may have to do with being in hotels most nights, but the sleep tracker has similar results when I am at home sleeping on the new mattress I am now using, since I took my own advice earlier this year and replaced my mattress and pillow. Each of us should get the best sleep possible and consult a doctor if we are having problems.
What about your sleep cycles? Learn more about sleep cycles and consider using a sleep tracker or an app that will help you understand your sleep cycles. Each of us will progress through the sleep cycle differently. I have learned that I get a better quality and quantity of sleep on the days I exercise, avoid caffeine after 3:00pm, avoid alcohol and heavy foods after 6:00pm, go to bed no later than 10:00pm, and stop using a computer or other devices at 9:00pm.
