Musculoskeletal effects of 5 days of bed rest with and without locomotion replacement training

verfasst von

E. Mulder, G. Clément, D. Linnarsson, W. H. Paloski, F. P. Wuyts, J. Zange, P. Frings-Meuthen, B. Johannes, V. Shushakov, M. Grunewald, N. Maassen, J. Buehlmeier, J. Rittweger

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.

Externe Organisation(en)

Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)
Université internationale de l'espace (ISU)
Karolinska Institutet
University of Houston
Universiteit Antwerpen (UAntwerpen)
Medizinische Hochschule Hannover (MHH)
Rheinische Friedrich-Wilhelms-Universität Bonn

Typ

Artikel

Journal

European Journal of Applied Physiology

Band

115

Seiten

727-738

Anzahl der Seiten

12

ISSN

1439-6319

Publikationsdatum

04.2015

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Orthopädie und Sportmedizin, Öffentliche Gesundheit, Umwelt- und Arbeitsmedizin, Physiologie (medizinische)

Ziele für nachhaltige Entwicklung

SDG 3 – Gute Gesundheit und Wohlergehen

Elektronische Version(en)

https://doi.org/10.1007/s00421-014-3045-0 (Zugang: Offen)