ABSTRACT

PURPOSE:

‍Caffeine, often in the form of coffee, is frequently supplemented by athletes in an attempt to facilitate improved performance during exercise. The aim of the present study was to investigate the effectiveness of coffee ingestion as an ergogenic aid prior to a one-mile (1609 m) race.

METHODS:

‍In a double-blind, randomised, crossover, placebo-controlled design 13 trained male runners completed a one-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 mm·ss) compared with DEC (04:39:14 ± 00:11:21 mm·ss; P=0.018; 95%CI: -0.11, -0.01; d=0.32) and 1.9% faster compared with PLA (04:41:00 ± 00:09:57 mm:ss; P=0.006; 95%CI: -0.15, -0.03; d=0.51). A large trial and time interaction for salivary caffeine concentration was observed (P<0.001; η2P=0.69) 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=0.602; 95%CI: -0.09, 0.03; d=0.17). Furthermore, only trivial differences for blood glucose (P=0.839; η2P=0.02) and lactate (P=0.096; η2P=0.18), and maximal heart rate (P=0.286; η2P=0.13) were observed between trials.

CONCLUSIONS:

‍The results of the present study show that 60 minutes after ingesting 0.09 g·kg-1 of caffeinated coffee one-mile race performance was enhanced by 1.9% and 1.3% compared with placebo and decaffeinated coffee respectively, in trained male runners.