Efeito da suplementação de cafeína sobre o dano muscular induzido pelo exercício

• Ano de defesa: 2022
• Autor(a) principal: Caldas, Leonardo Carvalho
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Doutorado em Educação Física; Centro de Educação Física e Desportos; UFES; Programa de Pós-Graduação em Educação Física
• Palavras-chave em Português: Contrações excêntricas; Dano muscular; Dor muscular de início tardio; subject.br-rjbn; Educação Física
• Link de acesso: http://repositorio.ufes.br/handle/10/16526

EIMD is a common phenomenon when performing unusual or strenuous exercise, characterized by physical damage to muscle fibers at the macro and microstructural level, involving sarcomeres, cell membrane and connective tissue. EIMD is characterized by a temporary decrease in force production capacity, reduced range of motion, swelling of the affected limb, increased stiffness and delayed onset muscle soreness. Previous studies have shown that caffeine ingestion attenuates delayed onset muscle soreness, reduces strength loss, and reduces circulating levels of blood markers of muscle damage. However, the evidence is not conclusive and the beneficial effects of caffeine intake on EIMD are not always observed. Differences between studies may be related to several possible factors, such o timing of supplementation (pre- or post-event causing muscle damage), duration of supplementation protocol (e.g., acute versus chronic), and methods used to assess muscle damage. (e.g. pain perception, loss of strength and blood markers of damage). Several studies have investigated the effect of caffeine using only one indirect marker of muscle damage, although it is unclear whether caffeine has a direct effect on each of these markers or whether there is an interaction between them. For example, would the decrease in pain perception with caffeine supplementation also be related to lower loss of strength and circulating levels of creatine kinase after EIMD? Or do these effects happen independently? The thesis is presented in the Scandinavian model, that is, in the format of two articles containing the following structures: Introduction, material and methods, results, discussion and conclusion. For the first study, a systematic review was performed following the steps as proposed by the Cochrane Handbook. The electronic search included four databases: PubMed, Scopus, Cochrane and Bireme and the following Boolean terms and operators were used: “caffeine” AND “muscle damage” OR “exercise induced muscle damage” OR “soreness” OR “delayed onset muscle soreness” OR “pain”. The search was conducted between December 2020 and January 2022. Fourteen studies were included, evaluating the effect of caffeine on indirect markers of muscle damage, including blood markers (nine studies), pain perception (six studies) and maximal voluntary contraction force (four studies). It was observed in four studies that repeated administration of caffeine between 24 and 72 h after muscle damage can attenuate the perception of pain in magnitudes ranging from 3.9% to 26%. The use of a single dose of caffeine pre-exercise (five studies) or post exercise (one study) did not alter the circulating blood levels of creatine kinase (CK). Caffeine supplementation appears to attenuate pain perception, but this does not appear to be related to an attenuation of EIMD, per se. Furthermore, the effect of caffeine supplementation after muscle damage on strength recovery remains inconclusive due to the low number of studies found (four studies) and controversial results for both dynamic and isometric strength tests. The second study aimed to investigate the effect of caffeine supplementation on muscle damage induced by exercise involving the upper limb. Twelve men with a mean age of 27.2 ± 3.3 SD, with a mean consumption of 230 ± 159 mg/day of caffeine and no previous experience with strength training in the last 3 months were recruited. A double-blind crossover design lasting 4 weeks, separated by 1 week of whashout, was used. The subjects received doses of 6mg/kg of body weight of caffeine or placebo ingested at the moments: pre, post eccentric exercise, 24h, 48h and 72h after muscle damage. Using the factorial ANOVA Supplementation x Time (2x5), reductions in maximum voluntary contraction force, reduction in range of motion, increase in muscle soreness and increase in circumference of the exercised limb were observed, which lasted for 72 hours after eccentric exercise. Furthermore, no difference was observed between caffeine and placebo conditions. This study concluded that caffeine supplementation was not able to attenuate EIMD in the upper limb in men who are regular caffeine consumers.