A friend recently sent me a link to The power of the Sleep Cycle
, whose author claims that sleeping 90 minutes in the evening and then 3 hours at night leaves him quite rested.
The idea behind this practice is that a sleep cycle is 90 minutes long, and that the way to make the most of sleep is to get in as many of these full cycles as possible. One source quoted in the article mentions that sleeping through a full four cycles (6 hours) of sleep may be more restful than sleeping 8 or 10 hours and waking in the middle of a cycle, but that hardly confirms the 90-minutes-followed-by-180 theory. In fact, the same source claims that the REM stages of the cycle get longer as the number of contiguous cycles increases, which would seem to indicate that I'd feel better after 7.5 hours (five cycles) than after just 3 hours (two cycles).
Nonetheless, I'm intrigued by the idea of getting only 4.5 hours of sleep a night, and I'd like to try it. I'm worried, however, about the long-term consequences, and, I must admit, I'm a bit skeptical about being able to function well on only three sleep cycles per 24 hours.
What's the science behind all of this? Will I be rested and happy after sleeping 4.5 hours, or am I destined for regret and caffeine?