Sleep is the cheapest performance upgrade you are not using

Major health bodies, including the US Centers for Disease Control and Prevention and the American Academy of Sleep Medicine, recommend that adults get seven or more hours of sleep a night. Surveys regularly find that around a third of adults get less.

What short sleep costs you

• Focus and memory: the brain consolidates what you learned during sleep.
• Mood: irritability and anxiety rise after even one short night.
• Long-term health: chronic short sleep is linked to higher risks of obesity, heart disease and type 2 diabetes.

Habits that actually help

Keep a fixed wake-up time, even at weekends. It anchors your body clock more than a fixed bedtime does.

Get daylight in the morning. Ten to twenty minutes outside helps set your internal clock.

Watch caffeine after lunch. Its effects can last many hours after your last cup.

Make the bedroom cool, dark and quiet — and keep screens out of it if you can.

You cannot catch up on a week of short nights with one long lie-in. Consistency beats compensation.

If you regularly snore loudly, stop breathing during sleep or feel exhausted despite enough time in bed, talk to a doctor: sleep disorders are common and treatable.