Review of Caffeine as a Running Performance Aid

Caffeine is the world’s most popular stimulant — and it’s also one of the most studied ergogenic aids in sports. From coffee to gels to pills, many runners use it to sharpen focus and push through fatigue. But how effective is it, and are there downsides?

How Caffeine Works

Caffeine blocks adenosine receptors in the brain, reducing the perception of fatigue. It also stimulates adrenaline release, mobilizes fat stores for energy, and may improve neuromuscular efficiency.

Benefits for Runners

1. Enhanced Alertness: Especially useful for early-morning races.
   
2. Reduced Perceived Effort: Makes hard paces feel easier.
   
3. Improved Endurance: Studies show caffeine can improve time-to-exhaustion by 10–20%.
   
4. Accessibility: Found in coffee, tea, gels, and sports drinks.
   
   

Potential Drawbacks

• GI Issues: Some runners experience cramps or urgency.
• Sleep Disruption: Late-day use can affect rest.
• Individual Sensitivity: Effects vary widely; some are “non-responders.”
• Overuse Risks: High doses may cause jitters, anxiety, or elevated heart rate.
  
  

Best Practices

• Typical effective dose: 3–6 mg per kg body weight, taken 30–60 minutes pre-race.
  
• Test caffeine in training before race day.
  
• Consider small mid-race doses for marathons and ultras.
  
  

Verdict

Caffeine is one of the most effective legal performance aids for runners. The key is experimenting with timing and dosage to find what works for your body — and remembering that more isn’t always better.

- Edward