title: The 2nd Berlin BedRest Study: protocol and implementation.
abstract: Long-term bed-rest is used to simulate the effect of spaceflight on the human body and test different kinds of countermeasures. The 2nd Berlin BedRest Study (BBR2-2) tested the efficacy of whole-body vibration in addition to high-load resisitance exercise in preventing bone loss during bed-rest. Here we present the protocol of the study and discuss its implementation. Twenty-four male subjects underwent 60-days of six-degree head down tilt bed-rest and were randomised to an inactive control group (CTR), a high-load resistive exercise group (RE) or a high-load resistive exercise with whole-body vibration group (RVE). Subsequent to events in the course of the study (e.g. subject withdrawal), 9 subjects participated in the CTR-group, 7 in the RVE-group and 8 (7 beyond bed-rest day-30) in the RE-group. Fluid intake, urine output and axiallary temperature increased during bed-rest (p < .0001), though similarly in all groups (p > or = .17). Body weight changes differed between groups (p < .0001) with decreases in the CTR-group, marginal decreases in the RE-group and the RVE-group displaying significant decreases in body-weight beyond bed-rest day-51 only. In light of events and experiences of the current study, recommendations on various aspects of bed-rest methodology are also discussed.
authors.affiliation: Charité Universitatsmedizin Berlin, Center of Muscle and Bone Research, Hindenburgdamm 30, 12203 Berlin, Germany. belavy@gmail.com
authors.forename: D L
authors.initials: DL
authors.lastname: Belavý
authors.forename: O
authors.initials: O
authors.lastname: Bock
authors.forename: H
authors.initials: H
authors.lastname: Börst
authors.forename: G
authors.initials: G
authors.lastname: Armbrecht
authors.forename: U
authors.initials: U
authors.lastname: Gast
authors.forename: C
authors.initials: C
authors.lastname: Degner
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authors.lastname: Beller
authors.forename: H
authors.initials: H
authors.lastname: Soll
authors.forename: M
authors.initials: M
authors.lastname: Salanova
authors.forename: H
authors.initials: H
authors.lastname: Habazettl
authors.forename: M
authors.initials: M
authors.lastname: Heer
authors.forename: A
authors.initials: A
authors.lastname: de Haan
authors.forename: D F
authors.initials: DF
authors.lastname: Stegeman
authors.forename: P
authors.initials: P
authors.lastname: Cerretelli
authors.forename: D
authors.initials: D
authors.lastname: Blottner
authors.forename: J
authors.initials: J
authors.lastname: Rittweger
authors.forename: C
authors.initials: C
authors.lastname: Gelfi
authors.forename: U
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authors.lastname: Kornak
authors.forename: D
authors.initials: D
authors.lastname: Felsenberg
mesh_terms: D000328:Adult; D001510:Bed Rest / Q000009:adverse effects*; D001604:Berlin; D005081:Exercise Therapy / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D010809:Physical Fitness / Q000502:physiology*; D016896:Treatment Outcome; D014732:Vibration / Q000627:therapeutic use; D018474:Weightlessness Simulation / Q000009:adverse effects*; D055815:Young Adult