Urine Caffeine Concentration in Doping Control Samples from 2004 to 2015

Abstract

The ergogenic effect of caffeine is well-established, but the extent of its consumption in sport is unknown at the present. The use of caffeine was considered “prohibited” until 2004, but this stimulant was moved from the List of Prohibited Substances to the Monitoring Program of the World Anti-Doping Agency to control its use by monitoring urinary caffeine concentration after competition. However, there is no updated information about the change in the use of caffeine as the result of its inclusion in the Monitoring Program. The aim of this study was to describe the changes in urine caffeine concentration from 2004 to 2015. A total of 7488 urine samples obtained in official competitions held in Spain and corresponding to athletes competing in Olympic sports (2788 in 2004, 2543 in 2008, and 2157 in 2015) were analyzed for urine caffeine concentration. The percentage of samples with detectable caffeine (i.e., >0.1 μg/mL) increased from ~70.1%, in 2004–2008 to 75.7% in 2015. The median urine caffeine concentration in 2015 (0.85 μg/mL) was higher when compared to the median value obtained in 2004 (0.70 μg/mL; p < 0.05) and in 2008 (0.70 μg/mL; p < 0.05). The urine caffeine concentration significantly increased from 2004 to 2015 in aquatics, athletics, boxing, judo, football, weightlifting, and rowing (p < 0.05). However, the sports with the highest urine caffeine concentration in 2015 were cycling, athletics, and rowing. In summary, the concentration of caffeine in the urine samples obtained after competition in Olympic sports in Spain increased from 2004 to 2015, particularly in some disciplines. These data indicate that the use of caffeine has slightly increased since its removal from the list of banned substances, but urine caffeine concentrations suggest that the use of caffeine is moderate in most sport specialties. Athletes of individual sports or athletes of sports with an aerobic-like nature are more prone to using caffeine in competition.

The Effects of Caffeine Ingestion on Measures of Rowing Performance: A Systematic Review and Meta-Analysis

“…Of the analyzed athletes, the authors reported that rowers were among the highest users of caffeine. In a subsequent analysis from 2015, rowers were again found to have very high urine caffeine concentration after competition [5].…”

“…Given the widespread anecdotal use of caffeine in rowers [4,5], and the lack of scientific consensus on the effects of caffeine on rowing performance, this paper aims to conduct a systematic review and a meta-analysis of studies examining the effects of caffeine ingestion on rowing performance. Such an analysis would be of interest to the following: (a) athletes competing in rowing; (b) sports nutritionists; (c) coaches; and (d) researchers interested in further exploring the influence of caffeine supplementation on rowing performance.…”

Effects of Caffeine and Coffee on Human Functioning

“…The clear evidence provided by this special issue confirming the ergogenic effect of caffeine might be behind the slight increase in the use of caffeine in sports since its removal from the list of banned substances in 2004 [14]. By analyzing the concentration of caffeine in post-competition urine samples, it has been found that about three out of four athletes consume caffeine or caffeine-containing products to increase performance [14].…”

Inconsistency in the Ergogenic Effect of Caffeine in Athletes Who Regularly Consume Caffeine: Is It Due to the Disparity in the Criteria That Defines Habitual Caffeine Intake?

“…Nowadays, caffeine is the most popular psychoactive substance in the world and data on urine caffeine concentration suggests that it is widely used by athletes before competition to enhance physical and mental fitness [1,2]. The research supporting the ergogenic effects of acute caffeine intake in a variety of sporting disciplines and exercise scenarios is extensive, and the International Olympic Committee has recently classified caffeine as a substance that enhances performance based on this strong scientific evidence [3].…”