Context: Caffeine, often in the form of coffee, is frequently used as a supplement by athletes in an attempt to facilitate improved performance during exercise.
Purpose: To investigate the effectiveness of coffee ingestion as an ergogenic aid prior to a 1-mile (1609 m) race.
Methods: In a double-blind, randomized, cross-over, and placebo-controlled design, 13 trained male runners completed a 1-mile race 60 minutes following the ingestion of 0.09 g·kg-1 coffee (COF), 0.09 g·kg-1 decaffeinated coffee (DEC), or a placebo (PLA). All trials were dissolved in 300 mL of hot water.
Results: The race completion time was 1.3% faster following the ingestion of COF (04:35.37 [00:10.51] min:s.ms) compared with DEC (04:39.14 [00:11.21] min:s.ms; P = .018; 95% confidence interval [CI], -0.11 to -0.01; d = 0.32) and 1.9% faster compared with PLA (04:41.00 [00:09.57] min:s.ms; P = .006; 95% CI, -0.15 to -0.03; d = 0.51). A large trial and time interaction for salivary caffeine concentration was observed (P < .001; [Formula: see text]), with a very large increase (6.40 [1.57] μg·mL-1; 95% CI, 5.5-7.3; d = 3.86) following the ingestion of COF. However, only a trivial difference between DEC and PLA was observed (P = .602; 95% CI, -0.09 to 0.03; d = 0.17). Furthermore, only trivial differences were observed for blood glucose (P = .839; [Formula: see text]) and lactate (P = .096; [Formula: see text]) and maximal heart rate (P = .286; [Formula: see text]) between trials.
Conclusions: The results of this study show that 60 minutes after ingesting 0.09 g·kg-1 of caffeinated coffee, 1-mile race performance was enhanced by 1.9% and 1.3% compared with placebo and decaffeinated coffee, respectively, in trained male runners.
Keywords: caffeine; competition; ergogenic aid; middle-distance running.