Changes in muscle size, architecture, and neural activation after 20 days of bed rest with and without resistance exercise
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Deutscher übersetzter Titel: | Änderungen in Muskelgröße und -architektur und in der neuromuskulären Erregbarkeit nach 20 tägiger Bettruhe mit und ohne Krafttraining |
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Autor: | Kawakami, Y.; Akima, H.; Kubo, K.; Muraoka, Y.; Hasegawa, H.; Kouzaki, M.; Imai, M.; Suzuki, Y.; Gunji, A.; Kanehisa, H.; Fukunaga, T. |
Erschienen in: | European journal of applied physiology |
Veröffentlicht: | 84 (2001), 1-2, S. 7-12, Lit. |
Format: | Literatur (SPOLIT) |
Publikationstyp: | Zeitschriftenartikel |
Medienart: | Gedruckte Ressource Elektronische Ressource (online) |
Sprache: | Englisch |
ISSN: | 1439-6319, 0301-5548 |
DOI: | 10.1007/s004210000330 |
Schlagworte: | |
Online Zugang: | |
Erfassungsnummer: | PU199912501277 |
Quelle: | BISp |
TY - JOUR AU - Kawakami, Y. A2 - Kawakami, Y. A2 - Akima, H. A2 - Kubo, K. A2 - Muraoka, Y. A2 - Hasegawa, H. A2 - Kouzaki, M. A2 - Imai, M. A2 - Suzuki, Y. A2 - Gunji, A. A2 - Kanehisa, H. A2 - Fukunaga, T. DB - BISp DP - BISp KW - Bettruhe KW - Erregbarkeit, neuromuskuläre KW - Kraftdefizit KW - Krafttraining KW - Muskelfunktion KW - Muskelmorphologie KW - Muskelquerschnitt KW - Prävention KW - Skelettmuskulatur KW - Sportmedizin KW - Training, präventives LA - eng TI - Changes in muscle size, architecture, and neural activation after 20 days of bed rest with and without resistance exercise TT - Änderungen in Muskelgröße und -architektur und in der neuromuskulären Erregbarkeit nach 20 tägiger Bettruhe mit und ohne Krafttraining PY - 2001 N2 - Nine healthy men carried out head-down bed rest (BR) for 20 days. Five subjects (TR) performed isometric, bilateral leg extension exercise every day, while the other four (NT) did not. Before and after BR, maximal isometric knee extension force was measured. Neural activation was assessed using a supramaximal twitch interpolated over voluntary contraction. From a series cross-sectional magnetic resonance imaging scans of the thigh, physiological cross-sectional areas (PCSA) of the quadriceps muscles were estimated (uncorrected PCSA, volume/estimated fibre length). Decrease in mean muscle force after BR was greater in NT (-10.9 (SD 6.9)%, P<0.05) than in TR (0.5 (SD 7.9)%, not significant). Neural activation did not differ between the two groups before BR, but after BR NT showed smaller activation levels. Pennation angles of the vastus lateralis muscle, determined by ultrasonography, showed no significant changes in either group. The PCSA decreased in NT by -7.8 (SD 0.8)% (P<0.05) while in TR PCSA showed only an insignificant tendency to decrease (-3.8 (SD 3.8)%). Changes in force were related more to changes in neural activation levels than to those in PCSA. The results suggest that reduction of muscle strength by BR is affected by a decreased ability to activate motor units, and that the exercise used in the present experiment is effective as a countermeasure. Verf.-Referat L2 - https://dx.doi.org/10.1007/s004210000330 DO - 10.1007/s004210000330 SP - S. 7-12 SN - 1439-6319 JO - European journal of applied physiology IS - 1-2 VL - 84 M3 - Gedruckte Ressource M3 - Elektronische Ressource (online) ID - PU199912501277 ER -