Caffeine
Caffeine is the world's most widely consumed psychoactive substance and one of the most well-researched supplements. A-GRADE evidence for aerobic exercise performance improvement (64 studies, 799 participants - moderate improvement). Also A-grades for cycling performance. B-GRADE for headache relief (5 studies, 1503 participants), sleep duration reduction (expected effect), and adrenaline increase. Works via adenosine receptor antagonism, increasing alertness and reducing fatigue perception. Safe for most adults at moderate doses (up to 400mg/day). Ergogenic effects are robust and well-established across endurance, strength, and cognitive domains.
Quick Answer
What it is
Caffeine is the world's most widely consumed psychoactive substance and one of the most well-researched supplements. A-GRADE evidence for aerobic exercise performance improvement (64 studies, 799 participants - moderate improvement).
Key findings
- Grade A: Aerobic Exercise Metrics (Aerobic Exercise Performance)
- Grade B: Agility (Aerobic Exercise Performance)
- Grade B: Headaches (Pain Relief)
Safety
No specific caution or interaction language was detected in the current summary/outcome notes.
ℹ️ Quick Facts: Caffeine
Quick Facts: Caffeine
- Best Evidence:Grade A
- Conditions Studied:24
- Research Outcomes:123
- Grade A Findings:3
- Grade B Findings:5
- Key Effect:Aerobic Exercise Performance
Detailed Outcomes
Evidence by Condition
Best grade per condition (each condition may have multiple outcomes)
Research Citations (54)
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