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Twins Bed Rest Project: Effects of LBNP/Exercise Countermeasure on Body Composition
Author(s) -
Amorim Fabiano T.,
Schneider Suzanne M.,
Lee Stuart M.C.,
Watenpaugh Donald E,
Macias Brandon R,
Tse Kevin Y,
Hargens Alan R
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.a1252-a
Subject(s) - supine position , lean body mass , trunk , medicine , body weight , treadmill , lower body , zoology , physical therapy , biology , ecology
This study determined whether supine treadmill exercise within a lower body negative pressure chamber (LBNP EX ) prevents changes in body composition during 30d of 6° head‐down bed rest (BR). METHODS Thirteen pairs of monozygous twins (6 male, 7 female pairs; 26±4 yrs) participated in this study. One sibling of each pair of twins was randomly assigned to either an exercise (EX: 166±9 cm; 59.6±9.0 kg) or a non‐exercise (CON: 168±12 cm; 62.7±11.9 kg) group. The LBNP EX protocol consisted of 40‐min interval exercise at 40–80% of pre‐BR VO 2peak followed by 5 min resting LBNP 6d·wk −1 . LBNP was adjusted to produce a footward force equivalent to 1.0–1.2 times body weight (53±5 mmHg for 1 body weight). Caloric intake was controlled to maintain body mass during BR. DEXA was used to measure lean and fat mass before and after BR. A two‐way ANOVA was used for comparisons. RESULTS After 30d of BR, the CON group had reduced lean leg mass (LLM) and increased whole body (BFM) and trunk fat mass (TFM) (p<0.05). The EX group had no significant changes after BR.CONCLUSIONS Changes in body composition were prevented by LBNP EX during 30d of BR in men and women. LBNP EX may help to prevent lower limb sarcopenia and change in body fat during space flight. Supported by a NASA grant NAG9‐1425 to ARH and by a NIH grant MO1 RR00827 to the UCSD GCRC.