Details
| Originalsprache | Englisch |
|---|---|
| Seiten (von - bis) | 727-738 |
| Seitenumfang | 12 |
| Fachzeitschrift | European Journal of Applied Physiology |
| Jahrgang | 115 |
| Ausgabenummer | 4 |
| Frühes Online-Datum | 26 Nov. 2014 |
| Publikationsstatus | Veröffentlicht - Apr. 2015 |
| Extern publiziert | Ja |
Abstract
Objectives: The present study evaluated the effectiveness of a short and versatile daily exercise regime, named locomotion replacement training (LRT), to maintain muscle size, isometric strength, power, and endurance capacity of the leg muscles following 5 days of head-down tilt (HDT) bed rest. Methods: 10 male subjects (age 29.4 ± 5.9 years; height 178.8 ± 3.7 cm; body mass 77.7 ± 4.1 kg) performed, in random order, 5 days of 6° head-down tilt bed rest (BR) with no exercise (CON), or BR with daily 25 min of upright standing (STA) or LRT. Results: Knee extensor and plantar flexor cross-sectional area (CSA) were reduced by 2–3 % following bed rest (P < 0.01) for CON and STA, yet maintained for LRT. Knee extensor isometric strength (MVC) decreased by 8 % for CON (P < 0.05), was maintained for STA, and increased with 12 % for LRT (P < 0.05). Plantar flexor MVC remained unaltered during the study. Maximum jump height declined (~1.5 cm) for all conditions (P < 0.001). Neural activation and knee extensor fatigability did not change with bed rest. Bone resorption increased during BR and neither LRT nor STA was able to prevent or attenuate this increase. Conclusion: LRT was adequate to maintain muscle size and to even increase knee extensor MVC, but not muscle power and bone integrity, which likely requires more intense and/or longer exercise regimes. However, with only some variables showing significant changes, we conclude that 5 days of BR is an inadequate approach for countermeasure assessments.
ASJC Scopus Sachgebiete
- Medizin (insg.)
- Orthopädie und Sportmedizin
- Medizin (insg.)
- Öffentliche Gesundheit, Umwelt- und Arbeitsmedizin
- Medizin (insg.)
- Physiologie (medizinische)
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in: European Journal of Applied Physiology, Jahrgang 115, Nr. 4, 04.2015, S. 727-738.
Publikation: Beitrag in Fachzeitschrift › Artikel › Forschung › Peer-Review
}
TY - JOUR
T1 - Musculoskeletal effects of 5 days of bed rest with and without locomotion replacement training
AU - Mulder, E.
AU - Clément, G.
AU - Linnarsson, D.
AU - Paloski, W. H.
AU - Wuyts, F. P.
AU - Zange, J.
AU - Frings-Meuthen, P.
AU - Johannes, B.
AU - Shushakov, V.
AU - Grunewald, M.
AU - Maassen, N.
AU - Buehlmeier, J.
AU - Rittweger, J.
N1 - Funding Information: We thank the subjects for participating in this study and the staff of the DLR operational study team for supervising the bed rests. The study was funded by the European Space Agency (Contract Number 22126/08/NL/VJ). Publisher Copyright: © 2014, The Author(s).
PY - 2015/4
Y1 - 2015/4
N2 - Objectives: The present study evaluated the effectiveness of a short and versatile daily exercise regime, named locomotion replacement training (LRT), to maintain muscle size, isometric strength, power, and endurance capacity of the leg muscles following 5 days of head-down tilt (HDT) bed rest. Methods: 10 male subjects (age 29.4 ± 5.9 years; height 178.8 ± 3.7 cm; body mass 77.7 ± 4.1 kg) performed, in random order, 5 days of 6° head-down tilt bed rest (BR) with no exercise (CON), or BR with daily 25 min of upright standing (STA) or LRT. Results: Knee extensor and plantar flexor cross-sectional area (CSA) were reduced by 2–3 % following bed rest (P < 0.01) for CON and STA, yet maintained for LRT. Knee extensor isometric strength (MVC) decreased by 8 % for CON (P < 0.05), was maintained for STA, and increased with 12 % for LRT (P < 0.05). Plantar flexor MVC remained unaltered during the study. Maximum jump height declined (~1.5 cm) for all conditions (P < 0.001). Neural activation and knee extensor fatigability did not change with bed rest. Bone resorption increased during BR and neither LRT nor STA was able to prevent or attenuate this increase. Conclusion: LRT was adequate to maintain muscle size and to even increase knee extensor MVC, but not muscle power and bone integrity, which likely requires more intense and/or longer exercise regimes. However, with only some variables showing significant changes, we conclude that 5 days of BR is an inadequate approach for countermeasure assessments.
AB - Objectives: The present study evaluated the effectiveness of a short and versatile daily exercise regime, named locomotion replacement training (LRT), to maintain muscle size, isometric strength, power, and endurance capacity of the leg muscles following 5 days of head-down tilt (HDT) bed rest. Methods: 10 male subjects (age 29.4 ± 5.9 years; height 178.8 ± 3.7 cm; body mass 77.7 ± 4.1 kg) performed, in random order, 5 days of 6° head-down tilt bed rest (BR) with no exercise (CON), or BR with daily 25 min of upright standing (STA) or LRT. Results: Knee extensor and plantar flexor cross-sectional area (CSA) were reduced by 2–3 % following bed rest (P < 0.01) for CON and STA, yet maintained for LRT. Knee extensor isometric strength (MVC) decreased by 8 % for CON (P < 0.05), was maintained for STA, and increased with 12 % for LRT (P < 0.05). Plantar flexor MVC remained unaltered during the study. Maximum jump height declined (~1.5 cm) for all conditions (P < 0.001). Neural activation and knee extensor fatigability did not change with bed rest. Bone resorption increased during BR and neither LRT nor STA was able to prevent or attenuate this increase. Conclusion: LRT was adequate to maintain muscle size and to even increase knee extensor MVC, but not muscle power and bone integrity, which likely requires more intense and/or longer exercise regimes. However, with only some variables showing significant changes, we conclude that 5 days of BR is an inadequate approach for countermeasure assessments.
KW - Bone markers
KW - Exercise countermeasure
KW - Fatigability
KW - Hypokinesia
KW - Skeletal muscle
UR - http://www.scopus.com/inward/record.url?scp=84925500446&partnerID=8YFLogxK
U2 - 10.1007/s00421-014-3045-0
DO - 10.1007/s00421-014-3045-0
M3 - Article
C2 - 25425257
AN - SCOPUS:84925500446
VL - 115
SP - 727
EP - 738
JO - European Journal of Applied Physiology
JF - European Journal of Applied Physiology
SN - 1439-6319
IS - 4
ER -