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dc.contributor.advisorKyröläinen, Heikki
dc.contributor.advisorAvela, Janne
dc.contributor.authorMesquita, Ricardo N. O.
dc.date.accessioned2017-10-09T14:59:49Z
dc.date.available2017-10-09T14:59:49Z
dc.date.issued2017
dc.identifier.otheroai:jykdok.linneanet.fi:1725773
dc.identifier.urihttps://jyx.jyu.fi/handle/123456789/55591
dc.description.abstractSeveral studies have documented the ergogenic effects of caffeine, but its mechanisms of action are not fully understood yet. The purpose of this study was to investigate the underlying mechanisms that may explain any caffeine-induced effects in a non-fatigued state and during exhaustive stretch-shortening cycle exercise (SSC). Eighteen males participated in this randomised, double-blind, placebo-controlled crossover trial. Baseline measures of plantarflexion force, drop jump, squat jump, voluntary activation, neuromuscular transmission, contractile properties, H-reflex, corticospinal excitability, short-intracortical inhibition, intracortical facilitation (ICF), corticospinal silent period (CSP) and blood biomarkers were made before administration of caffeine (6 mg•kg-1 ) or placebo. After a 1-hour rest, participants repeated the baseline measures, followed by a fatigue protocol that consisted of SSC exercise until exhaustion on a sledge apparatus by repeating series of 40 bilateral rebound jumps, with resting periods of 3 min. Neuromuscular testing was carried out throughout and after the fatigue protocol. Caffeine enhanced pre to postcapsule drop jump height, decreased CSP, suppressed a time-related decrease in ICF and mobilized free fatty acids. At the group level, caffeine did not alter the number of sets completed. However, ten responders were identified and pre to postcapsule changes in inhibitory mechanisms were significantly correlated with the number of sets completed in the caffeine trial. Responders also benefited from a decreased sense of effort during exercise and from an accelerated recovery of neuromuscular transmission failure after fatigue. The observed effects of this drug on the neuromuscular system may be explained by the reversal of inhibitory effects of adenosine. Effects of caffeine are highly dependent on individual responsiveness and thus, examination of its effects on an individual basis is highly recommended.en
dc.format.extent1 verkkoaineisto (101 sivua)
dc.language.isoeng
dc.rightsJulkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty.fi
dc.rightsThis publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited.en
dc.subject.otherfatigue
dc.subject.othercentral fatigue
dc.subject.otherperipheral fatigue
dc.subject.otherperipheral transmission failure
dc.subject.othertranscranial magnetic stimulation
dc.subject.otherrate of perceived exertion
dc.subject.otherexercise performance
dc.subject.otherexertion
dc.subject.othersoleus
dc.titleMechanisms of action of caffeine in a non-fatigued state and during fatiguing exercise : responders versus non-responders
dc.identifier.urnURN:NBN:fi:jyu-201710093965
dc.type.ontasotPro gradufi
dc.type.ontasotMaster's thesisen
dc.contributor.tiedekuntaLiikuntatieteellinen tiedekuntafi
dc.contributor.tiedekuntaFaculty of Sport and Health Sciencesen
dc.contributor.laitosSport and Health Sciencesen
dc.contributor.laitosLiikunta- ja terveystieteetfi
dc.contributor.yliopistoUniversity of Jyväskyläen
dc.contributor.yliopistoJyväskylän yliopistofi
dc.contributor.oppiaineLiikuntafysiologiafi
dc.contributor.oppiaineExercise Physiologyen
dc.subject.methodVaihtovuoroinen tutkimus
dc.date.updated2017-10-09T14:59:49Z
dc.rights.accesslevelrestrictedAccessfi
dc.contributor.oppiainekoodi5011
dc.subject.ysotranskraniaalinen magneettistimulaatio
dc.subject.ysorasituskokeet
dc.subject.ysolihakset
dc.subject.ysorasitus
dc.subject.ysoväsyminen
dc.subject.ysosuorituskyky
dc.subject.ysokofeiini
dc.subject.ysoliikuntafysiologia
dc.rights.accessrightsAineistoon pääsyä on rajoitettu tekijänoikeussyistä. Aineisto on luettavissa Jyväskylän yliopiston kirjaston arkistotyöasemalta. Ks. https://kirjasto.jyu.fi/fi/tyoskentelytilat/laitteet-ja-tilat.fi
dc.rights.accessrightsThis material has a restricted access due to copyright reasons. It can be read at the workstation at Jyväskylä University Library reserved for the use of archival materials: https://kirjasto.jyu.fi/en/workspaces/facilities.en


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