Here is a concise summary of the text:
**Title:** The Only Supplement Proven to Increase Concentration: Caffeine
**Key Points:**
1. **The Culprit Behind Fatigue:** Adenosine, a molecule that accumulates in neurons, reducing focus and energy.
2. **The Solution:** Caffeine, which can cross the blood-brain barrier, mimics adenosine, and boosts dopamine and adrenaline.
3. **Effective Dosage:** At least 75mg of caffeine (≈ 1 cup of coffee) to improve focus, with effects noticeable within 15 minutes to 1 hour.
4. **Optimal Consumption:**
* Timing: Based on individual needs (e.g., morning, pre-workout, or post-lunch).
* Limit: Up to 400mg per day to avoid side effects (insomnia, anxiety, headaches).
* Avoid consuming caffeine at least 6 hours before bedtime.
5. **Important Note:** Caffeine is not a substitute for sleep, exercise, hydration, and a balanced diet, which are also crucial for a focused and healthy routine.
Here are the key facts extracted from the text, numbered and in short sentences:
**Physiology and Adenosine**
1. Adenosine is a small molecule that accumulates in neurons over the course of the day.
2. Adenosine reduces the release of messenger molecules between neurons, slowing them down.
3. Adenosine also reduces the release of dopamine and adrenaline, responsible for pleasure and motivation.
4. Adenosine accumulation in neurons is the chemical signature of tiredness.
5. During sleep, accumulated adenosine in neurons is transformed into other molecules or eliminated.
**Blood-Brain Barrier**
6. The blood-brain barrier separates blood from the brain, preventing dangerous substances from reaching the nervous system.
7. For a supplement to affect the brain, it must overcome the blood-brain barrier.
**Caffeine**
8. Caffeine is a stimulant found in coffee, teas, energy drinks, medicines, chocolate, and supplements.
9. Caffeine can cross the blood-brain barrier and reach the brain quickly.
10. Caffeine mimics adenosine, occupying some of its places in neurons, delaying the fatigue signal.
11. With less adenosine action, caffeine allows for more dopamine and adrenaline release.
12. At least 75 milligrams of caffeine (about 1 cup of coffee) is needed to increase focus.
13. It takes 15 minutes to an hour for caffeine to start making you feel more awake and alert.
**Caffeine Usage and Limitations**
14. Consuming caffeine 2-3 hours after lunch can help with afternoon focus.
15. Caffeine is not a substitute for sleep; its effects are limited with chronic sleep deprivation.
16. After 4 days of sleeping less than 7 hours, caffeine's alertness effect is reduced.
17. Healthy adults can safely consume up to 400 mg of caffeine per day (excluding pregnant women).
18. Consuming over 400 mg of caffeine can lead to insomnia, accelerated heart rate, anxiety, and headaches.
19. Caffeine can be completely eliminated from the body in approximately 10 hours (half-life: 5 hours).
20. It's recommended to avoid caffeine for at least 6 hours before bedtime to ensure uninterrupted sleep.