Title
Less fatiguability in eccentric than concentric repetitive maximal muscle contractions
Document Type
Journal Article
Publication Title
European Journal of Applied Physiology
Publisher
Springer
School
School of Medical and Health Sciences / Centre for Human Performance
Funders
Japan Society for the Promotion of Science (JSPS) KAKENHI #19K19890 (Masatoshi Nakamura)
Abstract
Purpose: Changes in elbow flexion torque and biceps brachii electromyogram (EMG) activity over 30 repetitive maximal voluntary concentric-only (CON-only), eccentric-only (ECC-only), and alternative concentric and eccentric (CON-ECC, 30 concentric + 30 eccentric) contractions were examined to compare their muscle fatigue profiles. Methods: Fifteen healthy young men performed CON-only, ECC-only and CON-ECC in their maximal effort between 10° and 100° elbow flexion on an isokinetic dynamometer at an angular velocity of 30°/s with a 3-s rest between contractions in a randomised order with ≥ 3 days between conditions. Changes in torque and EMG over the repeated contractions and maximal voluntary isometric contraction (MVC-ISO) torque with EMG before the first contraction and immediately after the last contraction were compared among conditions by two-way repeated measures analysis of variance. Results: The torque decreased (p < 0.01) from the first to 30th contraction in CON-only (− 49.5 ± 11.0 %), ECC-only (− 32.2 ± 7.4 %), and concentric (− 62.3 ± 8.7 %) as well as eccentric phase (− 58.9 ± 9.3 %) in CON-ECC (− 46.0 ± 12.3 % overall). The magnitude of the decrease in the torque was greater (p < 0.01) for the CON-only than ECC-only, and the concentric than an eccentric phase in the CON-ECC. However, MVC-ISO torque decreased (p < 0.01) similarly after CON-only (− 42.9 ± 13.8 %) and ECC-only (− 40.1 ± 9.2 %), which was smaller (p < 0.01) than CON-ECC (− 56.8 ± 9.2 %). EMG over contractions decreased (p < 0.01) for all conditions similarly from the first to the last contraction (− 28.5 ± 26.8 %), and EMG in MVC-ISO also decreased similarly for all conditions (− 24.7 ± 35.8 %). Conclusion: These results suggest greater fatigue resistance in repetitive maximal eccentric than concentric contractions, but the fatigue assessed by MVC-ISO does not show it.
DOI
10.1007/s00421-023-05178-4
Access Rights
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Comments
Yoshida, R., Kasahara, K., Murakami, Y., Sato, S., Nosaka, K., & Nakamura, M. (2023). Less fatiguability in eccentric than concentric repetitive maximal muscle contractions. European Journal of Applied Physiology. Advance online publication. https://doi.org/10.1007/s00421-023-05178-4