title: [CAFFEINE INTAKE AND ITS EFFECT ON THE MAXIMAL AEROBIC SPEED CORRIDORS 800 -METER ATHLETES].
abstract: OBJECTIVE
  to check the effects of caffeine intake (3 mg/kg-1) and improved time to exhaustion limit of maximum aerobic speed and could modify blood lactate levels in 800-meter runners.
  
  
  METHODS
  the study is based on an experimental design, crossover, randomized and blind. 7 subjects (20 ± 3 years, 63 ± 6 kg, and 169.1 ± 7 cm) 800-meter runners, they should be competing for at least three years and be among the top 10 national ranking. They conducted a test timeout to exhaustion on a treadmill at maximum aerobic speed, where they ingested a capsule could contain caffeine (3 mg/kg-1) or placebo (sucralose). Lactate concentration at the rest and end of each test was measured.
  
  
  RESULTS
  caffeine intake showed a significant increase in the duration of the timeout relative to placebo (376 ± 137-457 ± 182 sec, respectively, p < 0.05). Regarding the blood lactate, no significant difference between the rest condition, the placebo and caffeine intake (p < 0.05).
  
  
  CONCLUSIONS
  the use of caffeine as an ergogenic aid, in doses of 3 mg/kg-1 significantly increased (p < 0.05) TLIM of VAM to exhaustion. This effect is an improvement in the performance of 800-meter runners. In turn, a significant increase in the concentrations of lactate, which could refer to the increase in intensity after caffeine intake work is appreciated.
authors.affiliation: Facultad de Ciencias de la Actividad Física, Universidad San Sebastián.. grosales@ug.uchile.cl.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Rosales Soto
authors.affiliation: Escuela de Salud, Duoc UC.. grosales@ug.uchile.cl.
authors.forename: Matías
authors.initials: M
authors.lastname: Monsálves Álvarez
authors.affiliation: Facultad de Filosofía y Educación, Pontificia Universidad Católica de Valparaíso.. grosales@ug.uchile.cl.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Yáñez Sepúlveda
authors.affiliation: Facultad de Ciencias de la Salud, Universidad San Sebastián. Chile.. sduran74@gmail.com.
authors.forename: Samuel
authors.initials: S
authors.lastname: Durán Agüero
mesh_terms: D000332:Aerobiosis / Q000187:drug effects*; D054874:Athletic Performance; D002110:Caffeine / Q000494:pharmacology*; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D012420:Running; D055815:Young Adult
chemical_list: D000697:Central Nervous System Stimulants; D019344:Lactic Acid; D002110:Caffeine