Why do I feel more tired when I sleep in?

Question

I almost always feel more tired after sleeping in.

For example, If I go to bed at 12:00am and wake up at 6:00am to an alarm, I feel somewhat tired, but after showering and eating breakfast, I usually do not feel tired at all.

If I go to bed at 12:00am and do not set an alarm, I usually wake up naturally, 8-9 hours later. I tend to feel much more tired when this happens, and for a much longer amount of time (usually until mid day/afternoon) even if I shower and eat right away like I would when waking up early.

I sometimes think that it is purely mental. Am I subconsciously forcing myself not to be tired on days that I must wake up early, but not when I am free to sleep in?

How is it possible that I consistently feel more rested after getting less sleep?

Answer 1

Good question Tehp.

You know what I also experienced that, according to Dr. Michael Breus, a Sleep Doctor that a sleep has its own cycle. The sleep-wake cycle follows a regular pattern (circadian rhythm) and when you sleep “too much” that pattern shifts. Circadian rhythms are the patterns of repeated activity associated with the environmental cycles of day and night that are repeated every 24 hours. Once our body clocks start to tell our body the wrong time we feel it in lethargy and fatigue. The clock says one thing and your body says another, very similar to jet lag.

The average sleep cycle lasts between 80-120 minutes (the average is 90 minutes) and the average person has five of these every night (totaling about 7.5 hours of deep sleep).

To avoid this feeling, you should go to bed and wake up at the same time every day. When you get up in the morning expose yourself to sunlight to boost your energy naturally and have regular exercise.

Answer 2

That is because your body isn't used to that much sleep. If you usually wake up after 6 hours and then one day after 8 or 9 hours, your body is kind of 'confused' and the metabolism falls asleep again, as you don't need it after the usual 6 hours of sleep.

https://www.wired.com/2014/07/whats-up-with-that-why-does-sleeping-in-just-make-me-more-tired/