Caffeine enhances upper body strength in resistance-trained women

Abstract

BackgroundResearch has indicated that low-to-moderate dosages of caffeine supplementation are ergogenic for sustained endurance efforts as well as high-intensity exercise. The effects of caffeine supplementation on strength-power performance are equivocal, with some studies indicating a benefit and others demonstrating no change in performance. The majority of research that has examined the effects of caffeine supplementation on strength-power performance has been carried out in both trained and untrained men. Therefore, the purpose of this study was to determine the acute effects of caffeine supplementation on strength and muscular endurance in resistance-trained women.MethodsIn a randomized manner, 15 women consumed caffeine (6 mg/kg) or placebo (PL) seven days apart. Sixty min following supplementation, participants performed a one-repetition maximum (1RM) barbell bench press test and repetitions to failure at 60% of 1RM. Heart rate (HR) and blood pressure (BP) were assessed at rest, 60 minutes post-consumption, and immediately following completion of repetitions to failure.ResultsRepeated measures ANOVA indicated a significantly greater bench press maximum with caffeine (p ≤ 0.05) (52.9 ± 11.1 kg vs. 52.1 ± 11.7 kg) with no significant differences between conditions in 60% 1RM repetitions (p = 0.81). Systolic blood pressure was significantly greater post-exercise, with caffeine (p < 0.05) (116.8 ± 5.3 mmHg vs. 112.9 ± 4.9 mmHg).ConclusionsThese findings indicate a moderate dose of caffeine may be sufficient for enhancing strength performance in resistance-trained women.

Acute Effects of Caffeine on Strength Performance in Trained and Untrained Individuals

“…This supports the collection of previous research documenting no significant increase [20,[23][24][25]. It does however contradict the research reporting significant increases of 1 RM bench press in resistance trained women [19] and men [20] although nonsignificant percentage increases of a similar degree were observed. Different muscle groups tested may have influence on degree of variation observed which may explain the results presented.…”

“…However, this phenomenon does not explain the variation in results observed in the present study between trained and untrained individuals, suggesting the cause for disparity may be more complex. Further research aimed at elucidating the main mechanisms involved in the variability between individuals has been previously reported [19,20]. This research provides the understanding that neither training status nor placebo effects are complex enough explanations for the continuing disparity in data.…”

“…However, reports of increased muscular strength performance are less established, and often more equivocal. In one study [19], a 5 mg.kg.bw -1 caffeine dose significantly enhanced bench press 1 RM in resistance trained females. Furthermore, 201 mg of caffeine significantly increased bench press 1 RM in trained men [20] but had no effect on leg extension 1 RM.…”

Eficácia ergogênica da suplementação de cafeína sobre o desempenho de força? Uma análise crítica.

“…Entretanto, estudos mais recentes têm demonstrado que a suplementação de cafeína também pode melhorar o desempenho físico em exercícios de alta intensidade e curta duração, bem como em exercícios de força (WARREN et al, 2010). Embora ainda haja a necessidade de maiores esclarecimentos sobre os possíveis mecanismos para tal melhora nessas atividades, pressupõe-se que a cafeína atue diretamente no músculo esquelético, aumentando a liberação de cálcio pelo retículo sarcoplasmático (TARNOPOLSKY; CUPIDO, 2000) e/ou reduzindo o acúmulo de potássio no interstício da célula muscular (MOHR; NIELSEN; BANGSBO, 2011 No que diz respeito aos efeitos da suplementação de cafeína sobre o desempenho de força, embora alguns estudos já tenham observados efeitos positivos desse suplemento nutricional (GOLDSTEIN et al, 2010;DUNCAN;OXFORD, 2011), outros estudos não tiveram sucesso em reproduzir tais achados (JACOBS; PASTERNAK; BELL, 2003;ROHMANN;FIRTH, 2008). Em virtude disso, o objetivo dessa revisão é sintetizar os achados da literatura acerca do efeito ergogênico da suplementação de cafeína sobre o desempenho de força, buscando explicar seus potenciais mecanismos de ação e o motivo da controvérsia quanto à sua eficácia neste tipo de atividade, bem como determinar as condições nas quais a cafeína pode beneficiar o desempenho de força.…”

Metabolic effects of a caffeinated sports drink consumed during a soccer match

“…Caffeine appears in doses ranging from 2 mg to 6 mg. kg -1 of body weight (BW) Gant, Ali, & Foskett, 2010;Goldstein, Jacobs, Whitehurst, Penhollow, & Antonio, 2010), reaching maximum doses of 9 mg. kg -1 (Graham & Spriet, 1991) in various forms of products including capsules (Ping, Keong, & Bandyopadhyay, 2010) of monohydrated caffeine powder added to carbohydrate drinks (Roberts et al, 2010) and chewing gum (Paton, Lowe, & Irvine, 2010).…”