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WISE‐2005: Lower Body Negative Pressure Treadmill and Resistive Exercise Countermeasures Maintain Physiologic Function in Women during 60‐days of Simulated Microgravity
Author(s) -
Macias Brandon Richard,
Schneider Suzanne,
Lee Stuart MC,
Guinet Patrick,
Hughson Richard,
Smith Scott,
Watenpaugh Donald,
Hargens Alan
Publication year - 2008
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.22.1_supplement.752.15
Subject(s) - supine position , medicine , orthostatic intolerance , cardiology , treadmill , physical therapy , orthostatic vital signs , blood pressure
We hypothesized that supine LBNP treadmill exercise combined with Flywheel resistive exercise maintains upright physiologic responses following 60‐days of head‐down tilt (HDT) bed rest (BR). METHODS: 16 healthy women (age 25–40 years) underwent 60‐days HDT (‐6°) BR. Women were assigned to either a non‐exercise control group (CON, n=8) or to an exercise group (EX, n=8). EX subjects performed a 40‐min, variable intensity LBNP exercise protocol at foot‐ward forces between 1.0–1.1 times body weight, followed by 10‐min of resting LBNP 3–4 days/week. Resistive exercise of maximal concentric and eccentric supine leg press and heel raise exercises were performed using a flywheel ergometer 2–3 days/week. IRBs approved this study with informed/written consent. RESULTS: Post‐BR VO 2 pk was not different in EX (−3.3±1.2%) but decreased significantly in CON (−21.2±2.1%), p< 0.05. Post‐BR orthostatic tolerance time (mean±se) decreased significantly less in EX (19.3±1.3 to 14.4±1.5 min) than in CON (17.5±0.1 to 9.1±1.5 min), p=0.03. Post‐BR muscle strength decreased significantly in CON, but was preserved in EX. Post‐BR bone resorption was greater than pre‐BR in both groups (p<0.05). Bone formation markers, were significantly elevated (p<0.05) in EX than in CON. CONCLUSIONS: Supine LBNP treadmill exercise along with flywheel resistive exercise maintains upright exercise capacity, orthostatic responses and muscle strength during 60‐days HDT BR. Supported by ESA, CSA, CNES; and NASA: NNJ04HF71G and NNJ04HF72G.