The Effect of Caffeine on Performance in Collegiate Tennis Players

Abstract

Background:

This study examined the efficacy of caffeine supplementation on tennis performance. The effect of a CYP1A2 polymorphism on the ergogenic response to caffeine was also investigated.

Methods:

Collegiate tennis players (eight men and eight women) completed two performance trials after the ingestion of either 6 mg/kg of caffeine or a placebo, provided in a double-blind fashion. The trials consisted of 45 minutes of intermittent treadmill exercise (TM; intended to mimic the intensities of game play), followed immediately by a tennis skill test (TST, which accessed stroke accuracy). Average ratings of perceived exertion and heart rate (HR) were recorded during TM and TST. DNA was obtained from whole blood and analyzed using polymerase chain reaction with allele-specific primers. Subjects were classified as AA homozygotes (n=7) or C allele carriers (n=9). Data were analyzed via repeated measures analysis of variance.

Results

: Caffeine significantly (p<0.05) improved the number of successful shots during the TST (2.1%; caffeine=295±11 shots; placebo=289±10 shots), but performance was not influenced by the genotype. There was a strong trend (p=0.052) suggesting a genotype×treatment interaction for HR during the TST, as caffeine raised HR in the AA homozygotes (placebo=149±13 beats/min; caffeine=155±17 beats/min), but not the C allele carriers (placebo=153±16 beats/min; caffeine=150±16 beats/min).

Conclusion

: Caffeine supplementation positively impacts tennis performance in collegiate tennis players. There may be preliminary support for a greater physiological effect of caffeine in AA homozygotes, though this had no apparent influence on tennis performance.