Acute caffeine supplementation and live match-play performance in team-sports: a systematic review (2000-2021): Caffeine and Team Sports

Background: Caffeine is a psycho-active stimulant that can improve physical and cognitive performance. This investigation systematically reviewed the evidence on the effects of acute caffeine ingestion on physiological parameters, physical and technical-skill performance during team-sport match-play. Methods: A literature search was performed in February 2021. Following the Preferred Reporting Items for Systematic-Reviews and Meta-Analysis (PRISMA) guidelines, studies were identified using PubMed, Web-of-Science, Scopus and SPORTDiscus. Results: Of 281 results, 13 studies met the inclusion criteria; with a targeted focus on randomised trials in high-performance athletes during match-play, involving caffeine and control conditions. The total number of participants was 213. All included studies adopted a randomised double-blinded cross-over design. In studies that measured physiological variables, responses to caffeine included higher peak (n = 6 of 8 [n of total studies measuring the variable]) and mean (n = 7 of 9) heart rates, and increased blood glucose (n = 2 of 2) and lactate (n = 2 of 2) concentrations. Improvements in physical performance were widely documented with caffeine, including greater distances covered (n = 7 of 7), distances covered at high-speed (n = 5 of 7) and impact frequencies (n = 6 of 8). From the three studies that assessed technical-skill performance, it appears caffeine intake may benefit gross skill performance, but has no effect, or negatively confounds finer technical-skill outcomes. Conclusions: There is compelling evidence that ingesting moderate caffeine doses (~3 to 6 mg·kg-1) ~60 minutes before exercise may improve physical performance in team-sports, whereas evidence is presently too scarce to draw confident conclusions regarding sport-specific skill performance.