'REM rules': Why sleep between 2-4 am is your brain's secret weapon

Produced by: Manoj Kumar

Madhavan’s Awakening

In a chat with prominent Indian neurologist Dr Sid Warrier, R Madhavan, 54, learned that sleep—not workouts or diets—delivers the greatest long-term health return.

Sleep Dividend

Dr Warrier stressed that sleep offers the “highest ROI on health,” calling it unmatched for brain preservation when practiced consistently over years.

Brain’s Resilience

While skipping a night is tolerable, years of poor sleep accumulate irreversible brain damage, triggering memory loss and risks of Alzheimer’s, warned Dr Warrier.

Hidden Havoc

Experts highlight that chronic sleep loss fuels hypertension, obesity, diabetes, and even stroke, as stress hormones surge and body functions crash.

Hunger Hormones

Lack of sleep skews hunger signals—leptin drops, ghrelin spikes—driving cravings, overeating, and eventual weight gain, explained Mahalakshmi.

Sleep Dosage

They note adults need 6-8 hours of sleep to maintain body repair cycles, while kids require much more to support growth.

Cortisol Surge

Chronic sleep debt raises cortisol levels, derails REM patterns, and triggers irritability, mood swings, and premature aging.

REM Repair

REM sleep, peaking between 2-4 AM, is vital for memory, emotions, and immunity, while neglecting it weakens the brain’s defenses.

Silent Decline

Experts caution that sleep neglect silently chips away at the brain, damaging focus, creativity, and emotional balance—often noticed only when it’s too late.