Key Takeaway
Umbrella review of meta-analyses confirming caffeine improves muscle strength, power, and endurance with effect sizes of 3-7%.
Summary
This umbrella review synthesized evidence from multiple meta-analyses on caffeine's effects on exercise performance. It represents the highest level of evidence synthesis available.
The review found consistent benefits across different types of exercise: muscle endurance (+6-7%), muscle strength (+3-4%), and aerobic endurance (+2-4%). The effects were observed at moderate doses and were relatively consistent across populations.
The paper provides strong evidence that caffeine is one of the most reliable ergogenic aids available.
Methods
- Umbrella review of meta-analyses
- Assessed quality of evidence
- Pooled effect sizes across studies
- Examined moderating factors
Key Results
- Muscle endurance: 6-7% improvement
- Muscle strength: 3-4% improvement
- Aerobic endurance: 2-4% improvement
- Anaerobic power: 3-4% improvement
- Effects consistent across most populations
Limitations
- Heterogeneous study protocols
- Publication bias possible
- Less evidence for untrained individuals
- Optimal timing not fully established