Purpose
The purpose of this study was to investigate whether variations in 163 C > A CYP1A2 genotypes (rs 762 551) (AA, AC, and CC) modify the ergogenic effects of caffeine (CAF) on strength, power, muscular endurance, agility, and endurance in adolescent athletes.
Methods
One hundred adolescents (age = 15 ± 2 years) were recruited. Participants ingested CAF (6 mg.kg−1) or placebo (PLA, 300 mg of cellulose) 1 hour before performing a sequence of physical tests: handgrip strength, vertical jumps, agility test, sit‐ups, push‐ups, and the Yo‐Yo intermittent recovery test level 1 (Yo‐Yo IR1).
Results
Compared to PLA, CAF enhanced (P < .05) sit‐up (CAF = 37 ± 9; PLA = 35 ± 8 repetitions) and push‐up repetitions (CAF = 26 ± 11; PLA = 24 ± 11 repetitions), and increased distance covered in Yo‐Yo IR1 test (CAF = 1010.4 ± 378.9; PLA = 903.2 ± 325.7 m). There was no influence of CAF on handgrip strength (CAF = 35.1 ± 8.9; PLA = 33.7 ± 8.7 kgf), countermovement jump height (CAF = 49.3 ± 12.6; PLA = 47.9 ± 13.8 cm), spike jump height (CAF = 54.2 ± 13.6; PLA = 52.9 ± 14.5 cm), and time in agility test (CAF = 15.8 ± 1.1; PLA = 15.9 ± 1.3 s, P > .05). When present, the ergogenic effect of CAF was not dependent of genotype.
Conclusion
CAF improves muscular endurance and aerobic performance in adolescent athletes, regardless of their 163 C > A CYP1A2 genotype.