Nikos V Margaritelis1,2, Anastasios A Theodorou3, Panagiotis N Chatzinikolaou2, Antonios Kyparos2, Michalis G Nikolaidis2, Vassilis Paschalis4. 1. Dialysis Unit, 424 General Military Hospital of Thessaloniki, Thessaloniki, Greece. 2. Department of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, Serres, Greece. 3. Department of Health Sciences, School of Sciences, European University Cyprus, Nicosia, Cyprus. 4. Department of Physical Education and Sport Sciences, School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Ethnikis Αntistasis 41, 17237, Athens, Greece. vpaschalis@phed.uoa.gr.
Abstract
PURPOSE: Acute high-intensity unaccustomed eccentric exercise performed by naive subjects is accompanied by disturbances in muscle damage biomarkers. The aim of the study was to investigate whether a causal relationship indeed exists between eccentric exercise and muscle damage. METHODS: Twenty-four men randomly assigned into a concentric only or an eccentric-only training group and performed 10 weeks of isokinetic resistance exercise (one session/week of 75 maximal knee extensors actions). Physiological markers of muscle function and damage (i.e., range of motion, delayed onset muscle soreness, isometric, concentric and eccentric peak torque) were assessed prior to and 1-3 and 5 days post each session. Biochemical markers of muscle damage (creatine kinase) and inflammation (C-reactive protein) were measured prior and 2 days post each session. RESULTS: After the first bout, eccentric exercise induced greater muscle damage compared to concentric exercise; however, during the nine following sessions, this effect progressively diminished, while after the 10th week of training, no alterations in muscle damage biomarkers were observed after either exercise protocol. Additionally, strength gains at the end of the training period were comparable between the two groups and were mode-specific. CONCLUSION: (1) eccentric exercise per se does not affect muscle damage biomarkers; (2) muscle damage occurs as a result of muscle unaccustomedness to this action type; (3) exercise-induced muscle damage is not a prerequisite for increased muscle strength. Collectively, we believe that muscle unaccustomedness to high-intensity eccentric exercise, and not eccentric exercise per se, is the trigger for muscle damage as indicated by muscle damage biomarkers.
RCT Entities:
PURPOSE: Acute high-intensity unaccustomed eccentric exercise performed by naive subjects is accompanied by disturbances in muscle damage biomarkers. The aim of the study was to investigate whether a causal relationship indeed exists between eccentric exercise and muscle damage. METHODS: Twenty-four men randomly assigned into a concentric only or an eccentric-only training group and performed 10 weeks of isokinetic resistance exercise (one session/week of 75 maximal knee extensors actions). Physiological markers of muscle function and damage (i.e., range of motion, delayed onset muscle soreness, isometric, concentric and eccentric peak torque) were assessed prior to and 1-3 and 5 days post each session. Biochemical markers of muscle damage (creatine kinase) and inflammation (C-reactive protein) were measured prior and 2 days post each session. RESULTS: After the first bout, eccentric exercise induced greater muscle damage compared to concentric exercise; however, during the nine following sessions, this effect progressively diminished, while after the 10th week of training, no alterations in muscle damage biomarkers were observed after either exercise protocol. Additionally, strength gains at the end of the training period were comparable between the two groups and were mode-specific. CONCLUSION: (1) eccentric exercise per se does not affect muscle damage biomarkers; (2) muscle damage occurs as a result of muscle unaccustomedness to this action type; (3) exercise-induced muscle damage is not a prerequisite for increased muscle strength. Collectively, we believe that muscle unaccustomedness to high-intensity eccentric exercise, and not eccentric exercise per se, is the trigger for muscle damage as indicated by muscle damage biomarkers.
Authors: Naomi M Cermak; Michael D Noseworthy; Jacqueline M Bourgeois; Mark A Tarnopolsky; Martin J Gibala Journal: Muscle Nerve Date: 2012-05-29 Impact factor: 3.217
Authors: Helenita Antonia de Oliveira; Ednei Luiz Antonio; Flávio André Silva; Paulo de Tarso Camillo de Carvalho; Regiane Feliciano; Amanda Yoshizaki; Stella de Souza Vieira; Brunno Lemes de Melo; Ernesto Cesar Pinto Leal-Junior; Rodrigo Labat; Danilo Sales Bocalini; José Antonio Silva Junior; Paulo José Ferreira Tucci; Andrey Jorge Serra Journal: J Sports Sci Date: 2018-03-26 Impact factor: 3.337