I have read from various (low quality) sources that practicing polyphasic sleep would add around 10 years to my lifespan vs. an average Western lifespan. Polyphasic sleep refers to the practice of sleeping multiple times in a 24-hour period—usually more than two, in contrast to biphasic sleep (twice per day) or monophasic sleep (once per day).
The polyphasic sleep concept is that, indeed, if you succeeded in sleeping 3 hours per day instead of the prescribed 8, starting at 20 years of age, you would gain over 11 years in an average Western lifespan.
Polyphasic sleep pattern or popularly known as Uberman sleep pattern refers to sleeping in short bursts of duration throughout the day and skipping altogether the one complete long stretch of normal night sleep. The recommendations can go from anywhere between 15 to 20 min. for every four hr time period to 30 min. for each block of 6 hr duration. So if your normal sleep requirement is of 7 hrs, with this sleep pattern you can easily save 5 hrs everyday! Assuming an average lifespan of 70 years and if one starts practicing this pattern at the age of 20, it “adds” up to a whopping 10 years to one’s lifespan. While this may sound very appealing, experts advise to employ caution.
One of you said that studies show that getting less than eight hours of sleep will reduces life expectancy. Even if, despite leaving me rested and happy, it does shorten my life by ten years, I will actually end up netting five years of “awake” time over a monophasic lifestyle. From my perspective, “life” only counts if you’re awake.
Is there any study on the effect of polyphasic sleep on lifespan?
I'm aware of the existence of the thread Does polyphasic sleep work? Does it have long-term or short-term side effects?, but it doesn't focus on the lifespan.