3 Why Do We Struggle with Rest and How Does Circadian Biology Work

A third of people regularly struggle to get a good night's rest, yet sleep occupies roughly one-third of human life. Oxford circadian neuroscientist Russell Foster and physiologist Dr Nerina Ramlakhan explore how internal biological clocks function and why modern lifestyles disrupt natural rest patterns. The main idea centers on understanding the circadian system as an internal timer that regulates bodily processes. Rather than obsessing over a strict eight-hour requirement, healthy sleep varies individually between six and eleven hours. Addressing sleep anxiety, screen exposure, and daily stress responses allows the nervous system to regain its natural restorative balance. Healthy sleep duration spans six to eleven hours depending on individual needs, disproving the rigid eight-hour standard. Waking up during the night is common, and biphasic or polyphasic sleep patterns often occur naturally as people age. Chronic sleep disruption is linked to increased risks for conditions like heart disease, diabetes, and suppressed immune function. During sleep, the brain's glymphatic system actively clears out metabolic toxins and beta-amyloid proteins. Working night shifts forces the body to rely on stress responses to stay awake, leading the World Health Organization to classify night shift work as a probable carcinogen. Adopting consistent morning light exposure and evening wind-down habits helps align internal biological rhythms with the environment. To support nervous system reset, physiologist Dr Nerina Ramlakhan outlines five targeted habits: consume breakfast within 30 to 45 minutes of waking, drink coffee only after eating and stop caffeine by midday, maintain hydration, begin preparing for bed between 9:30 and 10:00 PM without screens, and avoid screen-based blue light or stressful content before sleeping. How might checking digital tracking apps upon waking alter your personal stress levels and sleep perception throughout the day?