Effects of CYP1A2 and ADORA2A Genotypes on the Ergogenic Response to Caffeine in Professional Handball Players.
Study Goal
The researchers aimed to determine how genetic variations in CYP1A2 and ADORA2A influence the ergogenic response to acute caffeine intake in professional handball players.
Results Summary
Caffeine improved countermovement jump height, sprint velocity, and ball throwing velocity in professional handball players, but the ergogenic response was not significantly modulated by CYP1A2 or ADORA2A genotypes, except for a minor effect on 7m ball throwing.
Population
Thirty-one professional handball players (16 men, 15 women) with low daily caffeine consumption (60 ± 25 mg·d-1).
Effective Dosage
3 mg·kg-1·body mass, ingested 60 min before testing.
Duration
Single acute dose.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
acute caffeine intake | increase | ball throwing from 7 m | CYP1A2 AA homozygotes | - | ergogenic effect was higher | #1 |
caffeine | increase | CMJ height | professional handball players with low daily caffeine consumption | 2.8-4.3% | increased | #2 |
caffeine | increase | performance in the sprint velocity test | professional handball players with low daily caffeine consumption | 2.8-4.3% | increased | #3 |
caffeine | increase | ball throwing velocity from 9 m | professional handball players with low daily caffeine consumption | 2.8-4.3% | increased | #4 |
pre-exercise caffeine supplementation at a dose of 3 mg·kg-1·bm | increase | some neuromuscular aspects of handball performance | professional handball players with low daily caffeine consumption | - | can be considered as an ergogenic strategy to enhance | #5 |
acute caffeine intake | no change | - | CYP1A2 genotypes | - | ergogenic response was not modulated | #6 |
acute caffeine intake | no change | - | ADORA2A genotypes | - | ergogenic response was not modulated | #7 |
Previous investigations have found that several genes may be associated with the interindividual variability to the ergogenic response to caffeine. The aim of this study is to analyze the influence of the genetic variations in CYP1A2 (-163C > A, rs762551; characterized such as "fast" (AA genotype) and "slow" caffeine metabolizers (C-carriers)) and ADORA2A (1976T > C; rs5751876; characterized by "high" (TT genotype) or "low" sensitivity to caffeine (C-carriers)) on the ergogenic response to acute caffeine intake in professional handball players. Thirty-one professional handball players (sixteen men and fifteen women; daily caffeine intake = 60 ± 25 mg·d-1) ingested 3 mg·kg-1·body mass (bm) of caffeine or placebo 60 min before undergoing a battery of performance tests consisting of a countermovement jump (CMJ), a sprint test, an agility test, an isometric handgrip test, and several ball throws. Afterwards, the handball players performed a simulated handball match (2 × 20 min) while movements were recorded using inertial units. Saliva samples were analyzed to determine the genotype of each player for the -163C > A polymorphism in the CYP1A2 gene (rs762551) and for the 1976T > C polymorphism in the ADORA2A gene (rs5751876). In the CYP1A2, C-allele carriers (54.8%) were compared to AA homozygotes (45.2%). In the ADORA2A, C-allele carriers (80.6%) were compared to TT homozygotes (19.4%). There was only a genotype x treatment interaction for the ball throwing from 7 m (p = 0.037) indicating that the ergogenic effect of caffeine on this test was higher in CYP1A2 AA homozygotes than in C-allele carriers. In the remaining variables, there were no genotype x treatment interactions for CYP1A2 or for ADORA2A. As a whole group, caffeine increased CMJ height, performance in the sprint velocity test, and ball throwing velocity from 9 m (2.8-4.3%, p = 0.001-0.022, effect size = 0.17-0.31). Thus, pre-exercise caffeine supplementation at a dose of 3 mg·kg-1·bm can be considered as an ergogenic strategy to enhance some neuromuscular aspects of handball performance in professional handball players with low daily caffeine consumption. However, the ergogenic response to acute caffeine intake was not modulated by CYP1A2 or ADORA2A genotypes.