Table 2.
Performance variables during neuromuscular tests with ingestion of 3 mg·kg−1 bm of caffeine or a placebo in professional handball players with different genotypes in the −163C > A polymorphism of the CYP1A2 gene.
| Variable (Units) | CYP1A2 Genotype | Placebo | Caffeine | % Change | ES [95%CI] | Interaction |
|---|---|---|---|---|---|---|
| CMJ (cm) | AA | 32.91 ± 3.52 | 34.02 ± 4.44 | 3.4 | 0.28 [0.08, 0.48] | 0.903 |
| C-allele | 31.88 ± 9.22 | 33.25 ± 9.18 | 4.3 | 0.15 [0.01, 0.31] | ||
| SV (s) | AA | 4.75 ± 0.41 | 4.46 ± 0.27 | −5.0 | −0.84 [−1.04, −0.63] | 0.140 |
| C-allele | 4.77 ± 0.43 | 4.70 ± 0.49 | −1.5 | −0.15 [−0.32, −0.01] | ||
| MATT (s) | AA | 5.69 ± 0.38 | 5.70 ± 0.24 | 0.1 | 0.03 [−0.17, 0.23] | 0.451 |
| C-allele | 5.92 ± 0.65 | 5.89 ± 0.55 | −0.5 | −0.05 [−0.21, 0.11] | ||
| IHS (kg) | AA | 48.21 ± 14.51 | 48.24 ± 13.14 | 0.1 | 0.00 [−0.20, 0.20] | 0.069 |
| C-allele | 42.52 ± 9.46 | 44.88 ± 11.03 | 5.5 | 0.23 [0.07, 0.39] | ||
| BT7M (km/h) | AA | 83.62 ± 9.66 | 86.85 ± 9.49 | 3.9 | 0.34 [0.14, 0.54] | 0.037 * |
| C-allele | 81.94 ± 9.15 | 81.75 ± 7.99 | −0.2 | −0.02 [−0.19, 0.14] | ||
| BT7M + GK (km/h) | AA | 82.15 ± 8.53 | 85.46 ± 8.24 | 4.0 | 0.39 [0.19, 0.59] | 0.061 |
| C-allele | 81.81 ± 7.27 | 80.31 ± 5.90 | −1.8 | −0.23 [−0.39, −0.06] | ||
| BT9M (km/h) | AA | 82.31 ± 8.79 | 85.62 ± 7.52 | 4.0 | 0.40 [0.20, 0.60] | 0.207 |
| C-allele | 82.75 ± 6.87 | 84.31 ± 7.35 | 1.9 | 0.22 [0.06, 0.38] | ||
| BT9M + GK (km/h) | AA | 82.77 ± 8.11 | 86.46 ± 7.49 | 4.5 | 0.47 [0.27, 0.67] | 0.147 |
| C-allele | 84.50 ± 6.95 | 84.88 ± 6.93 | 0.4 | 0.05 [−0.11, 0.22] |
Abbreviations: CMJ: countermovement jump; SV: sprint velocity test; MATT; modified agility t-test; IHS: isometric handgrip strength; BT7M: ball throw 7-m, BT7M + GK: ball throw 7-m with goalkeeper; BT9M: ball throw 9-m; BT9 + GK: ball throw 9-m with goalkeeper; ES: effect size; CI: confidence interval. * Statistical significance was set at p < 0.05.