If I sleep more than 6 hours any day I don't feel that energetic as I do on most other days with a maximum of 5 hours sleep. I don't know if this is because me adopting to this habit very early in my life and persisting with it for now more than 20 years. TBH, upto now I don't have any health issues whatsoever. My immunity is good and on yearly health checkups I'm always fit and fine for most things. You'll be surprised if I tell you that I never ever had headache or any type of body pain that I've seen people start complaining in their early 40s. I don't catch cold so often as people do. I don't remember when was the last time I had fever.

I can only attribute all of these healthy conditions of mine to my for and fine parents who are in their 60s but they are relatively very fit. Thanks to God as well.

I've learnt meditation and yoda habits from my mother and eating good and healthy food from my father.

Please read this article to understand why some people need less sleep.

I can verify it for myself.