Scientists identify five sleep chronotypes as dark‑bath trend gains attention

Researchers at McGill University analyzed brain images, questionnaires and activity data from 27,000 participants in the UK Biobank and identified five distinct sleep patterns. The groups – high‑performing night owls, vulnerable night owls, male‑biased night owls, classic early birds and female‑biased early birds – show differing brain network efficiency, hormone levels and health risks such as depression, heart disease and diabetes.

A separate social‑media trend promotes taking a shower in complete darkness before bedtime. While no studies directly test this practice, experts note that reducing artificial light at night helps melatonin production and that a warm shower an hour before sleep can aid body‑temperature regulation, both of which may ease falling asleep. Safety precautions such as using low indirect lighting are advised, as the darkness itself carries fall‑risk.

Both pieces highlight how sleep habits, whether rooted in genetic chronotypes or bedtime routines, can influence overall health and underscore the importance of evidence‑based sleep hygiene.