title: Caffeine reduces reaction time and improves performance in simulated-contest of taekwondo.
abstract: The aim of this study was to investigate the effects of caffeine on reaction time during a specific taekwondo task and athletic performance during a simulated taekwondo contest. Ten taekwondo athletes ingested either 5 mg·kg⁻¹ body mass caffeine or placebo and performed two combats (spaced apart by 20 min). The reaction-time test (five kicks "Bandal Tchagui") was performed immediately prior to the first combat and immediately after the first and second combats. Caffeine improved reaction time (from 0.42 ± 0.05 to 0.37 ± 0.07 s) only prior to the first combat (P = 0.004). During the first combat, break times during the first two rounds were shorter in caffeine ingestion, followed by higher plasma lactate concentrations compared with placebo (P = 0.029 and 0.014, respectively). During the second combat, skipping-time was reduced, and relative attack times and attack/skipping ratio was increased following ingestion of caffeine during the first two rounds (all P < 0.05). Caffeine resulted in no change in combat intensity parameters between the first and second combat (all P > 0.05), but combat intensity was decreased following placebo (all P < 0.05). In conclusion, caffeine reduced reaction time in non-fatigued conditions and delayed fatigue during successive taekwondo combats.
authors: Sport Science Research Group, Department of Physical Education and Sports Science (CAV), Federal University of Pernambuco, Pernambuco 55608-680, Brazil. vander_ramon@hotmail.com.
authors: Victor G F
authors: VG
authors: Santos
authors: Sport Science Research Group, Department of Physical Education and Sports Science (CAV), Federal University of Pernambuco, Pernambuco 55608-680, Brazil. vander_ramon@hotmail.com.
authors: Vander R F
authors: VR
authors: Santos
authors: Sport Science Research Group, Department of Physical Education and Sports Science (CAV), Federal University of Pernambuco, Pernambuco 55608-680, Brazil. leandrocamati@hotmail.com.
authors: Leandro J C
authors: LJ
authors: Felippe
authors: Sport Science Research Group, Department of Physical Education and Sports Science (CAV), Federal University of Pernambuco, Pernambuco 55608-680, Brazil. wellingtonaljr@hotmail.com.
authors: Jose W
authors: JW
authors: Almeida
authors: Endurance Performance Research Group, School of Physical Education and Sport, University of Sao Paulo, Sao Paulo 05371-140, Brazil. bertuzzi@usp.br.
authors: Rômulo
authors: R
authors: Bertuzzi
authors: Endurance Performance Research Group, School of Physical Education and Sport, University of Sao Paulo, Sao Paulo 05371-140, Brazil. mapedamk@usp.br.
authors: Maria A P D M
authors: MA
authors: Kiss
authors: Sport Science Research Group, Department of Physical Education and Sports Science (CAV), Federal University of Pernambuco, Pernambuco 55608-680, Brazil. adrianosilva@usp.br.
authors: Adriano E
authors: AE
authors: Lima-Silva
mesh_terms: D000293:Adolescent; D000328:Adult; D056352:Athletes; D054874:Athletic Performance / Q000502:physiology*; D015992:Body Mass Index; D002110:Caffeine / Q000008:administration & dosage*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005080:Exercise Test / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007773:Lactates / Q000097:blood; D008297:Male; D005082:Physical Exertion / Q000187:drug effects; D011930:Reaction Time / Q000187:drug effects*; D064133:Sports Nutritional Physiological Phenomena / Q000187:drug effects*; D055815:Young Adult
chemical_list: D007773:Lactates; D002110:Caffeine