Data from: Sleep and subjective age: Protect your sleep if you want to feel young

The current studies examined the impact of insufficient sleep and
sleepiness on the subjective experience of age. Study 1, a cross-sectional
study of 429 participants (282 females (66%), 144 males, 3 other; age
range 18-70) showed that for each additional day of insufficient sleep in
the last 30 days, subjective age increased by 0.23 years. Study 2, an
experimental crossover sleep restriction study (N = 186; 102 females
(55%); 84 males; age range 18-46) showed that two nights of sleep
restriction (4h in bed/night) made people feel 4.44 years older compared
to sleep saturation (9h in bed/night). Additionally, moving from feeling
extremely alert (KSS score of 1) to feeling extremely sleepy (KSS score of
9) was associated with feeling 10 years older in both studies. These
findings provide compelling support for insufficient sleep and sleepiness
to exert a substantial influence on how old we feel, and that safeguarding
sleep is likely a key factor in feeling young.