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Table 3 Psychological measures recorded in each experimental group

From: Effects of caffeine supplementation on physical performance and mood dimensions in elite and trained-recreational athletes

  Elite Recreational p-values (ES)
Supplementation Group Supplementation x Group
Tension Caffeine 8.00 ± 4.99 4.30 ± 3.77 0.001** (0.51) 0.380 (0.05) 0.021* (0.29)
  Placebo 1.88 ± 3.56 2.90 ± 2.18
Depression Caffeine 3.63 ± 0.74 1.00 ± 1.25 0.894 (0.001) 0.036* (0.25) 0.242 (0.008)
  Placebo 2.88 ± 0.99 1.60 ± 3.69
Anger Caffeine 0.38 ± 1.06 2.40 ± 3.10 0.690 (0.01) 0.180 (0.08) 0.241 (0.11)
  Placebo 0.88 ± 1.81 1.40 ± 2.46
Vigor Caffeine 16.50 ± 2.62†# 13.00 ± 3.02 < 0.001*** (0.64) 0.119 (0.14) 0.004** (0.41)
  Placebo 12.62 ± 2.33 12.10 ± 2.85
Fatigue Caffeine 2.50 ± 3.50 2.60 ± 2.22 0.008** (0.36) 0.370 (0.05) 0.088 (0.17)
  Placebo 6.50 ± 4.54 3.60 ± 4.09
Confusion Caffeine 14.63 ± 3.54 12.20 ± 3.99 0.619 (0.02) 0.324 (0.06) 0.236 (0.09)
  Placebo 14.13 ± 4.36 13.40 ± 2.22
SVS Caffeine 40.63 ± 4.78 38.40 ± 5.44 < 0.001*** (0.59) 0.597 (0.02) 0.004** (0.41)
  Placebo 31.75 ± 7.78 36.80 ± 5.71
  1. Data are provided as the mean ± standard deviation. Adjusted values for the test statistic (F) and degrees of freedom (df) are shown when inequality of variances were found between groups
  2. Abbreviations: SVS: subjective vitality scale; ES: effect size
  3. *: p < 0.05; **: p < 0.01; ***: p < 0.001; †: significant differences for caffeine versus placebo at the group level; #: significant differences detected between elite and recreational athletes at the supplementation level