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dc.contributor.authorTikkanen, Olli
dc.date.accessioned2017-01-30T12:22:13Z
dc.date.available2017-01-30T12:22:13Z
dc.date.issued2006
dc.identifier.otheroai:jykdok.linneanet.fi:1672422
dc.identifier.urihttps://jyx.jyu.fi/handle/123456789/52896
dc.description.abstractAcute effects and recovery from exercise-induced fatigue is widely studied, but there is a lack of data concerning adaptations to acute fatigue with strength training. The purpose of this study was to examine neural responses to fatiguing heavy-resistance loading (HRL) and investigate neuromuscular adaptations with strength training. 75 healthy males (age 32 ± 8 years) divided randomly into the control (n=23) and training group (n=52) attained in 20 weeks of strength training. Before and after 20 weeks of strength training subjects carried out HRL comprising of 5 sets of 10 maximal bilateral knee extensions (10 RM). Maximal voluntary force, M-wave and twitch characteristics were measured before and after HRL and electromyographic (EMG) activity continuously during the HRL. Blood lactate concentrations were determined before, immediately after, and 15 and 30 minutes after the HRL. In the training group torque, power and load used during the HRL and maximal voluntary contraction (MVC) torque of knee extension and aEMG during MVC increased with strength training. MVC torque decreased on average 21 ± 12 % after HRL. There were no changes in lactate responses with training except pre-loading for the training group. In the control group lactate concentrations were significantly smaller at all time points at week 20 than at week 0. In the 4th and 5th sets mean power frequency of EMG was significantly lower (p<0.001) and in the 2nd set higher (p<0.05) after the training than before training. HRL resulted in significant decreases in peak tension (PT), contraction time (CT), rate of force development (RFD) and a significant increase in half-relaxation time (HRT) of the twitch. Relative, percentual changes (between pre-loading and post-loading state) in twitch characteristics were not significantly different between week 0 and week 20. HRT increased significantly due to HRL at week 0 (P<0.05) but not at week 20. No significant differences were observed in post-activation potentiation (PAP) between the corresponding week 0 and week 20 values. In the training group pre-loading PAP values were significantly different from post-loading values (P=0.01) at week 0, but not at week 20. An increase in duration of M-wave was observed after HRL in rectus femoris (P<0.05) and vastus medialis (P<0.05) before and after strength training. There were no significant changes in M-wave amplitude between pre- and post-loading values or any training induced changes in M-wave amplitude or duration. Torque, power and mean power frequency decreased during HRL. Neural input (indicated by aEMG) to muscle did not decrease during the HRL indicating that fatigue is mostly peripheral in origin in intermittent, multiple repetition loadings, such as the loading used in this study. All in all HRL induced fatigue changes were as expected from previous knowledge. Torque, power and neural input to muscles increased with strength training. Power was increased only for the two first sets and after that fatigue prevented usage of improved power. Strength training did not have effect on characteristics of the M-wave or twitch except HRT. Increase of HRT due to fatigue can be overcome by strength training. In general effects of strength training were in line with previous studies. In conclusion maximal strength oriented training is effective in improving torque and poen
dc.format.extent1 verkkoaineisto (64 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.otherStrength training
dc.subject.otherheavy-resistance loading
dc.subject.otherfatigue
dc.subject.otherEMG
dc.subject.othertwitch
dc.subject.otherM-wave
dc.titleNeural responses to fatiguing heavy-resistance loading before and after prolonged strength training
dc.identifier.urnURN:NBN:fi:jyu-201701301307
dc.type.ontasotPro gradufi
dc.type.ontasotMaster's thesisen
dc.contributor.tiedekuntaLiikuntatieteellinen tiedekuntafi
dc.contributor.tiedekuntaFaculty of Sport and Health Sciencesen
dc.contributor.laitosLiikuntabiologian laitosfi
dc.contributor.laitosDepartment of Biology of Physical Activityen
dc.contributor.yliopistoUniversity of Jyväskyläen
dc.contributor.yliopistoJyväskylän yliopistofi
dc.contributor.oppiaineValmennus- ja testausoppifi
dc.contributor.oppiaineScience in Sport Coaching and Fitness Testingen
dc.date.updated2017-01-30T12:22:13Z
dc.rights.accesslevelrestrictedAccessfi
dc.contributor.oppiainekoodi5013
dc.subject.ysovoimaharjoittelu
dc.subject.ysoelektromyografia
dc.subject.ysoväsymys
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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