Caffeine and L-Theanine: Does the Combination Improve Focus?
Studies commonly pair about 100 mg of caffeine with 200 mg of L-theanine. The combination may help attention with fewer jitters, but effects are small.
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Fad or fact? We check.
Every health trend promises something. We check which ones the research backs up.
Morning sunlight, cold plunges, magnesium before bed, zone 2 cardio: Fad or Fact takes the claims you hear on podcasts and social feeds back to the primary research. You get a direct answer up top, the mechanism, the dose and timing, and a link to every paper we relied on.
- Straight verdicts. The answer comes first, with no scrolling past a life story.
- Primary sources. Claims link back to the studies and episodes behind them.
- Kept current. Every page shows when it was last reviewed.
Topics
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Sleep
How to fall asleep faster, sleep deeper and wake up rested — timing, environment, and what actually helps.
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Light & Circadian Rhythm
Using morning sunlight, evening darkness and light timing to anchor your body clock.
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Cold & Heat Exposure
Cold plunges, cold showers and sauna — protocols, dosing and what the research supports.
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Supplements
Which supplements have real evidence behind them, which forms to take, and how to dose them.
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Exercise & Recovery
Training for strength, endurance and longevity, and recovering well between sessions.
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Focus & Cognition
Attention, focus, memory and mental performance — evidence-based tools and routines.
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Cold and Heat Exposure: What Does the Evidence Say?
An evidence-based overview of cold plunges, cold showers and sauna: what each does physiologically, common protocols and the limits of the research.
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How Can I Improve Focus and Cognitive Performance?
An evidence-based look at what reliably supports focus: sleep, exercise, light and caffeine first, with realistic expectations for supplements.
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How Can I Sleep Better? A Complete Evidence-Based Guide
A practical overview of the habits with the strongest evidence for better sleep: consistent timing, light, caffeine, temperature and nutrition.
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How Does Light Affect Your Circadian Rhythm? A Practical Guide
Light is the strongest signal for your body clock. Learn how morning light, evening dimming and darkness at night shape sleep timing and alertness.
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How Long Should You Get Morning Sunlight?
A simple morning sunlight routine: get outdoors within an hour of waking for roughly 10 to 30 minutes, longer on overcast days.
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How Many Hours Before Bed Should I Stop Caffeine?
Research suggests caffeine taken even six hours before bed can reduce sleep. A practical cutoff is at least eight hours before bedtime, adjusted to your sensitivity.
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How Much Creatine Should You Take per Day?
Studies commonly used 3 to 5 grams of creatine monohydrate daily, with or without a short loading phase. Here is the evidence and how timing fits in.
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How we work
Every page starts from a claim, usually from a long-form expert interview. We trace it to the papers it rests on, compare it with what other credible experts say, and tell you plainly when the evidence is strong, mixed or missing.
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