Table 1. Blood lactate (n = 15) and ammonia (n = 12) concentrations under the placebo and caffeine conditions before (Preexercise) and immediately (0 min) or 20 min after exercise (Postexercise). Preexercise Postexercise 0 min 20 min Lactate (mmol·L-1) Placebo 2.2 ± 0.4 18.2 ± 3.4 14.5 ± 3.0 Caffeine 2.3 ± 0.5 18.2 ± 2.9 14.5 ± 2.5 Ammonia (µg·dL-1) Placebo 78 ± 39 228 ± 55 182 ± 46 Caffeine 62 ± 28 232 ± 57 160 ± 57 The values are presented as the means ± SDs.