‘Enough’ sleep but never refreshed
Dr Srinivas M, neurologist, Apollo Hospitals, Seshadripuram, said non-REM sleep accounts for around 75-80% of total sleep and is important for physical and neurological restoration.
Dr Pavan Yadav MV, clinical director and senior consultant – interventional pulmonology & sleep medicine, KIMS Hospitals, Mahadevapura, said patients at his sleep clinic frequently complain that while they get adequate sleep, they do not wake up feeling fresh. When it got dark, the brain would secrete melatonin and we would naturally fall asleep,” he said. However, artificial lighting and prolonged exposure to LED screens, televisions, laptops and phones have changed this, he said. Dr Kranthi Mohan Chadalavada, consultant neurologist, Kauvery Hospital, Electronics City, said the number of hours spent in bed cannot be equated with sleep quality. “Fragmented sleep, insufficient deep or slow-wave sleep, circadian misalignment, and unrecognised disorders like sleep apnoea or periodic limb movements can all shorten effective restorative sleep even when total hours look adequate,” he said. Staying up late can particularly affect non-rapid eye movement (REM) sleep, doctors said. This is the stage most tied to physical restoration and next-day alertness,” he said. The brain’s glymphatic system also helps clear waste products and toxins from the brain,” he said. Dr Yadav said people working with teams abroad, those working from home and those worried about job security are often staying connected to work late into the night. Dr Yadav said people need to establish a consistent sleep routine and protect their sleeping hours.
“The quantity of sleep may be good, but the quality is often not. Human beings have something called a circadian rhythm. “When light falls on the retina, it signals to the brain that it is still daytime, which suppresses melatonin and delays sleep. Dr Chadalavada explained that deep, slow-wave sleep is concentrated in the initial sleep cycles. “Delaying sleep onset compresses the first sleep cycles, which is when slow-wave, deep non-REM sleep is most concentrated. “During non-REM sleep, the body carries out important repair processes. For many professionals, the problem continues even after the workday ends. “For a couple of hours before bedtime, they should avoid things that stimulate the brain — coffee, tea, energy drinks, sweets and alcohol. At least one hour before their bedtime, they should completely stop screen time — no phone, television or laptop.”
Earlier, our sleep cycle was naturally tuned to the sun.