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Nutrition Column

Caffeine Use in Sports

Everyone is familiar with caffeine in common beverages such as coffee, tea, and sodas. Caffeine has been shown to decrease tiredness, increase mental alertness, and improve mood, but the effects depend on variables such as quantity of caffeine consumed and caffeine tolerance, which is different for every person. Research has shown that caffeine also has beneficial effects for athletes preparing for competition. A recent review in the Journal of Strength and Conditioning discussed the role that caffeine plays in enhancing athletic performance.

Caffeine has been shown to increase work output and time to exhaustion in endurance exercises. Caffeine also improves peak power output, speed, and strength during sprint and power events that rely on immediate energy sources. Interestingly, no improvements were found for events lasting between 15 seconds and 3 minutes.

Caffeine stimulates the sympathetic nervous system, which is responsible for increasing heart rate, increasing blood flow, and causing arousal. Researchers hypothesize that caffeine improves the utilization of fat stores and conserves carbohydrates stores necessary for endurance. Others have proposed that caffeine works on the central nervous system by inhibiting the binding of adenosine, which slows nerve cell activity. The result is an increased sympathetic response and a more heightened awareness. Caffeine increases sprint and power performance by increasing intracellular calcium concentration and enhances other pathways necessary for peak force production.

Caffeine has a varying effect on different ages, genders, body type, and habituation levels. Lower caffeine doses may achieve maximal athletic performance with individuals who are non-users, but a higher dose of caffeine may be required for daily caffeine user. In recent studies, as little as 1 and as much as 13 mg/kg caffeine had positive effects on fatigue, endurance, sprint, and power events. Studies have also shown that only caffeine capsules improved performance significantly compared to placebo, coffee, and decaffeinated coffee plus caffeine. Caffeine reaches its peak plasma level between 30 and 75 minutes and is 75% cleared from the system within 6 to 7 hours of ingestion. If you are participating in an endurance event lasting longer than 6 hours, it may be beneficial to take multiple low-dosage caffeine capsules. Mixing caffeine with carbohydrates and/or amino acid rich fluids have shown promising results, but there is not enough information to conclude any absolute ergogenic effect.

It is a common belief that caffeine leads to dehydration and poor athletic performance, but recent evidence has shown otherwise. One study showed that acute caffeine ingestion among chronic consumers did not change fluid-electrolyte balance and physiologic responses during exercise in heat. Caffeine may be a great option for athletes looking to maximize endurance and power performances or helping you achieve a PR in your next endurance event.

Written by Ryan Serrano with Eric Sternlicht, Ph.D. Occidental College, Los Angeles, CA.