Caffeine, performance, and metabolism during repeated Wingate exercise tests

Abstract

Investigations examining the ergogenic and metabolic influence of caffeine during short-term high-intensity exercise are few in number and have produced inconsistent results. This study examined the effects of caffeine on repeated bouts of high-intensity exercise in recreationally active men. Subjects (n = 9) completed four 30-s Wingate (WG) sprints with 4 min of rest between each exercise bout on two separate occasions. One hour before exercise, either placebo (P1; dextrose) or caffeine (Caf; 6 mg/kg) capsules were ingested. Caf ingestion did not have any effect on power output (peak or average) in the first two WG tests and had a negative effect in the latter two exercise bouts. Plasma epinephrine concentration was significantly increased 60 min after Caf ingestion compared with P1; however, this treatment effect disappeared once exercise began. Caf ingestion had no significant effect on blood lactate, O2 consumption, or aerobic contribution at any time during the protocol. After the second Wingate test, plasma NH3 concentration increased significantly from the previous WG test and was significantly higher in the Caf trial compared with P1. These data demonstrate no ergogenic effect of caffeine on power output during repeated bouts of short-term, intense exercise. Furthermore, there was no indication of increased anaerobic metabolism after Caf ingestion with the exception of an increase in NH3 concentration.

The effects of different doses of caffeine on performance, rating of perceived exertion and pain perception in teenagers female karate athletes

“…The subjects in a study were male students of strength and conditioning and sport science and trained competitive male athletes; the performance task was cycle ergometer sprints, and 30 s Wingate test was conducted (Glaister et al, 2014;Woolf, Bidwell, Carlson, 2008). It seems that caffeine consumption in events that heavily rely on the glycolytic system (15 s to 3 min) has no positive impact on performance (possibly because of increase in plasma ammonia levels and decrease in intracellular pH) (Greer, McLean, Graham, 1998;Sökmen et al, 2008). Also, it is indicated that the sensitivity of caffeine consumers to the performance enhancing effects of caffeine is related to habitual intake (Woolf, Bidwell, Carlson, 2008).…”

Efeito da ingestão de cafeína no desempenho em corrida de 200 metros rasos

“…Somado a isso, a redução das concentrações plasmáticas de potássio (K + ) por meio do aumento da atividade da bomba de sódio e potássio (Na + /K + ATPase) no repouso (SIMMONDS et al, 2010) ou após o exercício (DOHERTY et al, 2002) podem proporcionar um ambiente favorável para o mecanismo de excitação-contração, melhorando o acoplamento das pontes cruzadas (LINDINGER et al, 1993). Por meio dos mecanismos descritos acima, pode-se prolongar (SIMMONDS et al, 2010) e/ou causar maior ativação (GREER et al, 1998) de unidades motoras durante este tipo de atividade.…”

A ingestão de cafeína não melhora o desempenho de atletas de judô

“…Entretanto, a utilização da cafeína como recurso ergogênico em atividades de alta intensidade e curta duração, tem gerado ao longo dos últimos anos controvérsias a cerca da sua eficácia (ANSELME et al, 1992;BRUCE et al, 2000;COLLOMP et al, 1991;DOHERTY, 1998;GREER et al, 1998;JACKMAN et al, 1996;WILLIAMS et al, 1988;WYSS et al, 1986).…”