Caffeine intake and its effect on the maximal aerobic speed corridors 800 -meter athletes

Abstract

Objectives: 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.