Sleep

Two mechanisms prepare you for falling asleep

The need to sleep increases with the time spent awake: this is sleep pressure. At the same time, the biological clock organizes periods favorable to wakefulness and rest, notably using light as a signal. The regularity of schedules and the difference between daylight and less lit evening help these two mechanisms to work together.

Caffeine blocks adenosine receptors, which is involved in sleep pressure. It reduces the feeling of fatigue without replacing rest. In a trial using a dose of four hundred milligrams, it still disrupted sleep when taken six hours before bedtime. The useful time varies depending on the dose and your sensitivity.

Fatigue changes the impression given by the face

Photographic experiments show that others detect lack of sleep in facial appearance. Finding sufficient nights sleep therefore helps above all to correct the tired component of the look and expression. The effect depends on your starting point: a person who already sleeps enough has less to gain by further extending their nights.

The skin also recovers during the nights

A study in sixty women associated poor sleep with more signs of skin aging and less effective recovery of the skin barrier after an experimental disturbance. This result supports the benefit of sleep for the skin, but remains an association: it does not promise quantified rejuvenation by improving nights.

Sleep accompanies physical progress

Sleep deprivation experiments have measured a reduction in the synthesis of muscle proteins. To gain volume, sufficient nights therefore complement training and diet. Keep these levers together: regular bodybuilding, appropriate protein intake and recovery time, rather than adding sessions by systematically shortening the nights.

Sleep can also make it easier to manage your diet. In a trial of eighty overweight adults who usually slept little, longer nights reduced average energy intake over the period studied. This illustrates a possible effect on eating habits; the evolution of the silhouette then depends on diet and activity over time.