How do sleep mechanisms work?

• Adenosine: A substance released in the brain from the moment you wake up. Its accumulation slows brain activity and causes sleepiness.
• Caffeine: Binds to receptors that induce sleepiness, blocking the effects of adenosine. The half-life of caffeine is about 5 hours. It is worth noting that contraceptive pills significantly slow down caffeine metabolism in the liver.
• Suprachiasmatic nucleus (SCN): Regulates the circadian rhythm—early in the morning it switches off melatonin production and raises the body’s internal temperature to help us wake up.

Melatonin and the circadian cycle

• Melatonin levels begin to rise around 9:00 PM, reaching their peak at around 3:00 AM.
• The half-life of melatonin is 3–4.5 hours.
• As a supplement, it is most effective for people over 55. The recommended dose is about 2 mg taken 1–2 hours before sleep (it should start working after about 30 minutes).
• Adolescents: During puberty, the internal clock shifts about 2 hours later. Girls are naturally “night owls” until around age 19, and boys until around age 21. Students should sleep 9–10 hours.

The relationship between sleep, diet, and the microbiome

The microbiome plays a crucial role in regulating stress and sleep. Bacteria in the large intestine produce 95% of our serotonin—a hormone that regulates appetite, sleep, libido, and digestion.

• Fiber and protein promote deeper sleep. Eating fiber-rich foods nourishes “good” gut bacteria, which produce chemicals that reduce stress and anxiety.
• Bacteroidetes bacteria produce the neurotransmitter GABA (which supports deep sleep), and the presence of Corynebacterium also improves sleep quality.
• Mediterranean diet: Provides anti-inflammatory components and reduces oxidative stress (removes free radicals), which lowers anxiety.
• Eating red meat may positively affect mood, likely due to iron and vitamin B12.
• Psychobiotics: A diverse microbiome influences the secretion of interleukin-6 (which regulates the immune system, sleep, and memory). Proper levels of dopamine, serotonin, and GABA calm the nervous system as effectively as medications such as Valium.

What to eat to support good bacteria (and good sleep)?

• Prebiotics (plant fibers that stimulate bacterial growth): legumes, onions, garlic, leeks, chicory, Jerusalem artichoke, whole grains, oats, barley, flaxseed, pears, apples, strawberries, blueberries, raspberries, seaweed, cocoa. Chicory root is a great caffeine-free coffee substitute.
• Probiotics (live bacterial cultures): yogurts, cheeses, fermented foods.
• Magnesium: Supplementation in older adults may help with falling asleep. Natural sources include avocado, green legumes, leafy vegetables, cashews, and almonds.

Practical rules for good sleep

• Set a consistent sleep window—go to bed and wake up at the same time (routine is key!).
• Avoid bright light in the evening. The bedroom should be cool, quiet, and dark.
• Eat your last meal at least 3 hours before bedtime. Avoid sugary nighttime snacks (follow the rule: eat from 8 AM to 6 PM, fast from 6 PM to 8 AM).
• At least an hour before bed, take a 10-minute hot bath with essential oils (lavender, vanilla, rose, bergamot help you fall asleep).
• Wind down: listen to relaxing music, make a to-do list for the next day (to clear your mind), or keep a gratitude journal (writing down 3 good things from the day effectively reduces stress).
• If you haven’t fallen asleep within 20 minutes of going to bed—get up and do something relaxing so you don’t associate the bed with frustration.
• Use yogic breathing (pranayama): place your hand on your abdomen, inhale deeply through your nose (count to 4), hold (count to 2), exhale through your mouth (count to 4).
• Alcohol in moderate amounts may reduce the risk of dementia, but it worsens sleep quality.
• Use reverse psychology: instead of thinking “I can’t fall asleep,” tell yourself “I actually enjoy being awake. I wonder how long I can last.”
• For daytime fatigue, a 15–20 minute nap in the early afternoon (about 7 hours after waking) works best. Fun fact: a cup of coffee before a 20-minute nap is more stimulating than either alone!

The impact of body weight and activity on sleep

• High-intensity interval training (HIIT) in the morning, preferably on an empty stomach, helps regulate the circadian rhythm. A series of resistance exercises after getting out of bed is also a good idea.
• Waist circumference should not exceed half of your height.
• Neck fat is a direct cause of snoring and sleep apnea. The maximum neck circumference for men is 43 cm and for women 41 cm. Losing just 2.5 cm in neck circumference can significantly improve sleep quality.
• Special CPAP devices are used in the treatment of snoring and sleep apnea.

How to change from a “night owl” to a “morning lark” (3-week plan)

To effectively shift your circadian rhythm, follow these 9 rules for 3 weeks:

1. Wake up at least 2 hours earlier than usual.
2. Go outside every morning to expose yourself to sunlight (you can also use a light therapy lamp for at least 30 minutes each morning).
3. Eat breakfast as soon as possible after waking up.
4. Exercise only in the morning.
5. Eat lunch at the same time every day.
6. Avoid caffeine after 4:00 PM.
7. Avoid naps after 4:00 PM.
8. Avoid bright light in the evening and go to bed 2 hours earlier than usual.
9. “Bore” your brain before sleep.

Sleep Restriction Therapy (SRT)

This is an effective method of treating insomnia. It involves deliberately limiting time spent in bed to the actual time spent sleeping, which increases so-called “sleep pressure.” The spoon test: If you fall asleep during the day (e.g., holding a spoon that wakes you when it drops) in less than 5 minutes, it indicates a serious sleep deficit. A result of 5–10 minutes is concerning, and 10–15 minutes indicates a mild issue.

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How to reduce the effects of shift work?

Below are tips for organizing shift work schedules that can improve employee performance and work quality. Applying these principles may also help prevent burnout by ensuring proper recovery.

• Shifts should rotate clockwise—morning, then afternoon, then night.
• It is worth arranging a place where a night shift worker can take a 20-minute nap (with supervisor approval). Research shows that such a nap significantly improves work quality.
• Whenever possible, try to ensure that “morning larks” do not have to work late, and “night owls” do not have to start work early.

Tips for night shift workers:

• It is recommended to sleep as many hours as possible before a night shift. Research shows that “banking sleep” before work is more effective than catching up afterward.
• Eat your main meal before midnight. After that, only light snacks are recommended, and it is best to avoid eating between 1:00 AM and 6:00 AM.
• Drink plenty of water and avoid carbonated drinks with added caffeine.
• Expose yourself to bright light at the beginning of your night shift.
• When planning sleep after work, wear dark sunglasses on your way home to avoid morning sunlight, which inhibits melatonin production.