The Sport Information Resource Centre
The Sport Information Resource Centre

Caffeine is the most consumed psychoactive substance in the world. It can be found in plants, prescription and non-prescription medication, cola soft drinks, and energy drinks. In the world of athletics, caffeine is an ergogenic aid, a substance used for a competitive advantage.

There is general agreement that caffeine does not appear to benefit athletes in short-term exercise, such as sprints, that have durations of a few seconds up to 90 seconds. These short-term exercises derive their energy from the anaerobic system. However, caffeine does seem to help endurance athletes in sports such as cycling, running and soccer.

How does it work? Muscles use glycogen to fuel the body and once depleted, exhaustion occurs. Another source of fuel the body uses is fat. Caffeine may encourage muscles to use fat as it mobilizes fat stores. This delays the depletion of muscle glycogen allowing an individual to exercise longer before exhaustion occurs.

The consumption of 3- 9 mg/kg of body weight has been found to increase endurance performance in cycling and running as observed in a laboratory setting. However the higher the mg/kg intake does not necessary equate to a better performance. Moderate caffeine ingestion of 5-6 mg/kg of body weight by cyclists during a laboratory setting has shown to increase performance in bouts of 4-6 minutes of intensity.

Though caffeine has been found to enhance performance, its effect on people varies depending on size, age, sex and how sensitive you are to caffeine. The side effects of caffeine can cause:

  • Restlessness
  • Nervousness
  • Insomnia
  • Tremors

When deciding to use caffeine it is wise to know that everybody will react differently and performance can decrease due to the side effects. Using it in training and evaluating how an individual responds to caffeine maybe the best way to approach it before using it in competition.

References from the SIRC Collection:

1. Aedma M, Timpmann S, íöpik V. Effect of Caffeine on Upper-Body Anaerobic Performance in Wrestlers in Simulated Competition-Day Conditions. International Journal Of Sport Nutrition & Exercise Metabolism. December 2013;23(6):601-609.

2. BROWN S, BROWN J, FOSKETT A. The Effects of Caffeine on Repeated Sprint Performance in Team Sport Athletes – A Meta-Analysis-. Sport Science Review. April 2013;22(1/2):25-32.

3. CHOW E. Caffeine and Performance. Bicycle Paper. March 2014;43(1):5.

4. Del Coso J, Muñoz G, Muñoz-Guerra J. Prevalence of caffeine use in elite athletes following its removal from the World Anti-Doping Agency list of banned substances. Applied Physiology, Nutrition & Metabolism. August 2011;36(4):555-561.

5. IRWIN C, DESBROW B, ELLIS A, O’KEEFFE B, GRANT G, LEVERITT M. Caffeine withdrawal and high-intensity endurance cycling performance. Journal Of Sports Sciences. March 2011;29(5):509-515.

6. Rogers P, Heatherley S, Mullings E, Smith J. Faster but not smarter: effects of caffeine and caffeine withdrawal on alertness and performance. Psychopharmacology. March 15, 2013;226(2):229-240.

7. Spence A, Sim M, Landers G, Peeling P. A Comparison of Caffeine Versus Pseudoephedrine on Cycling Time-Trial Performance. International Journal Of Sport Nutrition & Exercise Metabolism. October 2013;23(5):507-512.