Published in the British Journal of Nutrition, the study saw 14 male sprint swimmers perform two trials after consuming either a caffeinated energy drink (3 mg per kg) or the same drink without caffeine.
The swimmers performed a countermovement jump, a maximal handgrip test, a 50 meter simulated competition and a 45 second swim at maximum intensity in a swim ergometer. A blood sample was taken one minute after the ergometer test was completed.
The researchers from the Camilo José Cela University in Spain said the commercially available energy drink increased countermovement jump height – a backflip from standing, improved handgrip force in the right hand and increased peak power during a 45 second swim.
The caffeinated swimmers also took less time to complete the 50 metre swimming competition.
Meanwhile three out of 14 of the swimmers did not benefit from the energy drink intake.
They said the results showed moderate doses of caffeine could improve performance, rather than larger doses of over 6 mg often used by swimmers and other athletes.
The swimmers also completed a questionnaire to assess subjective feelings of power, endurance and fatigue as well as sleep quality, nervousness, gastrointestinal problems and other discomforts.
Any side effects from the caffeine intake were “marginal” at this low dosage, the researchers said.
“The low prevalence of side effects is particularly important in a sport like swimming in which major competitions require multiple performances over several days.”
The dosage given was well within the safe consumption levels set by the European Food Safety Authority (EFSA) earlier this year. EFSA said 400 mg of caffeine a day and 200 mg in one sitting was not a safety concern for adults.
A history of caffeine use
Caffeine can be used as an ergogenic aid—a substance that enhances speed and stamina.
The use of caffeine in sports – when urine concentration exceeded 12 µg/ml – was considered doping from 1984 until 2004.
Yet the World Anti-Doping Agency (WADA) moved caffeine off the list of banned substances in 2004 due to concerns over how to distinguish between ‘normal’ and performance enhancing intakes.
“Although caffeine was removed from the World Antidoping Agency (WADA) list of doping substances in 2004, national and international anti-doping authorities are still concerned about the use and misuse of this substance in sports. Caffeine has been periodically included in the WADA Monitoring Program.”
Source: British Journal of Nutrition
Published online ahead of print, doi:10.1017/S0007114515002573
“Acute consumption of a caffeinated energy drink enhances aspects of performance in sprint swimmers”
Authors: B. Lara, D. Ruiz-Vicente, F. Areces, J. Abián-Vicén, J. José Salinero, C. Gonzalez-Millán, C. Gallo-Salazar and J. Del Coso