Age

Age of one the major considerations in deciding on a polyphasic schedule. In particular, younger people are advised to avoid cutting too much sleep, as their brains could still developing and cutting sleep could detrimentally affect this process.

Background

Sleep baseline by age and stage

Younger people, particularly those under the ages of 16-20, have substantially higher sleep requirements than older adults. More specifically, they have a higher requirement of vital sleep stages (SWS and REM), which in general cannot be cut.

Moreover, light sleep, particularly the sleep spindles prominent in NREM2, has been suggested to play a role in brain development. Cutting light sleep via polyphasic adaptation could do harm this process and impair cognitive development.

Recommendations

Disclaimer: These values are based on community experience and do not constitute medical advice. You are responsible for your own health and well-being.

Age	Recommended minimum sleep	Recommended schedules
<16	7.5 hours	Extended biphasic schedules, non-reducing schedules
16-18	6 hours	Normal biphasic schedules, DC1-ext, Triphasic-ext, QC0
18-21	5 hours	E2, DC1, E3-ext
>21	4 hours	All other than Nap only, E4, and Trimaxion

In addition to health concerns, it is also important to note that cutting sleep is simply more difficult for younger individuals with higher baselines. While an adult might be able to handle E3 or DC2 relatively well as they are able to fulfill all of their vital sleep needs into the available sleep time in those schedules, a 15-year-old would not, as their sleep requirements will barely, if at all, fit into the total sleep on these.

Also, note that these values are for typical sleepers, and the exact values will differ based on your individual needs. The best way to determine your vital stage needs is by measuring a baseline with an EEG. With this information, you can be more informed about what schedules you should and should not try.