LAUSR

ABSTRACT Purpose No study has assessed the acute effect of caffeine supplementation on 100-m sprint running in athletics and caffeine’s net ergogenicity on 100-m sprint running remains unclear. We investigated the acute effects of caffeine supplementation on 100-m sprint running performance in a field test. Methods Thirteen male collegiate sprinters were subjected to 100-m sprint running time trials (TT) after the ingestion of 6 mg·kg−1 body weight caffeine or placebo supplementation in a double-blind, counterbalanced, randomized, and crossover design. Sprint velocity was measured with a laser system, and sprint time was calculated from the data in which the effects of environmental factors that would act as confounding factors on sprint time during TT were eliminated. Results The corrected 100-m sprint time was significantly shortened by 0.14 s with caffeine supplementation compared with placebo (placebo: 11.40 ± 0.39 s, caffeine: 11.26 ± 0.33 s; P = 0.007, g = −0.33). The corrected sprint time up to 60 m during TT was also significantly shorter with caffeine supplementation than with placebo (P = 0.002). Furthermore, the mean sprint velocity for splits of 0–10 and 10–20 m was significantly increased by caffeine supplementation (all P < 0.05). Conclusions Acute caffeine supplementation enhanced the corrected 100-m sprint time by improving the sprint performance in the first 60 m after more explosive acceleration in the early stage of the acceleration phase. Thus, for the first time, we directly demonstrated caffeine’s ergogenicity on 100-m sprint performance in athletics.