Table 2.

o 2 during exercise at 50 and 80% ofV˙o 2max 1, 3, and 6 h after caffeine or placebo ingestion

Time1 h3 h6 h
CaffeinePlaceboCaffeinePlaceboCaffeinePlacebo
Nonusers (n = 8)
 5 min 50%V˙o 2max 1.72 ± 0.381.66 ± 0.291.75 ± 0.321.78 ± 0.341.76 ± 0.381.71 ± 0.38
 5 min 80%V˙o 2max 2.85 ± 0.692.80 ± 0.632.88 ± 0.662.93 ± 0.672.83 ± 0.622.84 ± 0.68
 15 min 80%V˙o 2max 3.10 ± 0.90* 3.01 ± 0.733.08 ± 0.76* 3.06 ± 0.783.12 ± 0.88* 3.04 ± 0.81
Users (n = 13)
 5 min 50%V˙o 2max 1.86 ± 0.361.88 ± 0.371.88 ± 0.371.85 ± 0.291.90 ± 0.371.83 ± 0.34
 5 min 80%V˙o 2max 3.19 ± 0.733.21 ± 0.793.21 ± 0.723.15 ± 0.713.18 ± 0.703.19 ± 0.73
 15 min 80%V˙o 2max 3.44 ± 0.71* 3.39 ± 0.753.42 ± 0.76* 3.36 ± 0.713.43 ± 0.75* 3.37 ± 0.75
  • Values are means ± SD (in l/min).

  • * After 15 min at 80%V˙o 2max, caffeine produced a slight but significant increase in oxygen consumption (V˙o 2).