CAFFEINE SUPPLEMENTATION CAN MAKE RUNNERS RUN FURTHER AND IMPROVE PACE STRATEGY/A suplementacao de cafeina pode fazer corredores correrem mais e melhorar estrategia de ritmo

Caffeine can stimulate the central nervous system and thus increase exercise tolerance throughout rating perceived exertion (RPE) changes and it can change the pace strategy (PS) during a physical task. The aim of this study was to check if caffeine supplementation might promote changes in PS during a laboratory run test (LRT). In a double-blind, crossover, randomized and counterbalanced fashion, fifteen healthy-male (age: 24 [+ or -] 4.4 years; [VO.sub.2]max. 53 [+ or -] 5 ml.[Kg.sup.-1].[min.sup.(-1])) ingested 6 mgx[kg.sup.(-1]) of CAF or placebo supplementation, 60 minutes before the LRT. The LRT was three-minutes sets (at fixed speed, 1 km/h above Onset Blood Lactate Accumulation) until volitional exhaustion; Rest Time Interval (RTI) between sets were chosen by the participants in the first test (ranging from 30 to 60s). RPE, Heart Rate (HR) and blood plasma lactate concentration ([La]p) were collected at rest, immediately after each set and at the end of test. Time to exhaustion was higher for CAF (p= 0.014). RTI between sets was significantly lower in caffeine (p= 0.048) and this decreased significantly the time to perform a same distance (p= 0.034). Overall HR and [La]p was similar for both conditions (p= 0.252, p= 0.129, respectively). Despite similar overall RPE throughout test (p= 0.380), in caffeine, there was not a RPE abrupt increase similar to placebo. Caffeine supplementation can positively influence running PS (to decrease the RTI required for recovery between moments of high-intensity exercise), as well as, can make an individual run further (in the same event). Key words: Time to Exhaustion. Pace Strategy. Ergogenic Aid. Rating Perceived Exertion. A cafeína pode estimular o sistema nervoso central e aumentar a tolerância ao exercício por meio de mudanças na percepção subjetiva de esforço (PSE), isso pode mudar a estratégia de ritmo (ER) durante uma corrida. Nosso objetivo foi verificar se a suplementação de cafeína promove mudanças na ER durante um teste de corrida de laboratório (TCL). De modo duplo-cego, cruzado, randomizado e contrabalançado, quinze homens saudáveis (idade: 24 [+ or -] 4,4 anos, [VO.sub.2]max. 53 [+ or -] 5 ml.[Kg.sup.(-1]).[min.sup.-1]) ingeriram 6 mg/[kg.sup.-1] de cafeína ou placebo, 60 minutos antes do TCL. O TCL consistiu de séries de três minutos (velocidade fixada à 1 km/h acima do "Onset Blood Lactate Accumulation") até fadiga volicional; O Intervalo de Tempo de Descanso (ITD) entre as séries foi escolhido pel