WISE-2005: effect of aerobic and resistive exercises on orthostatic tolerance during 60 days bed rest in women

Autor: Guinet, Patrick, Schneider, Suzanne, Macias, Brandon, Watenpaugh, Donald, Hughson, Richard, Le Traon, Anne Pavy, Bansard, Jean-Yves, Hargens, Alan
Přispěvatelé: Service d'anesthésie réanimation chirurgicale [Rennes], Université de Rennes (UR)-Hôpital Pontchaillou, Laboratoire Traitement du Signal et de l'Image (LTSI), Université de Rennes (UR)-Institut National de la Santé et de la Recherche Médicale (INSERM), Department of Health, Exercise and Sports Sciences, The University of New Mexico [Albuquerque], Department of Orthopaedic Surgery, University of California [San Diego] (UC San Diego), University of California (UC)-University of California (UC)-UCSD Medical Center, Department of Integrative Physiology, University of North Texas Health Science Center [Fort Worth], Faculty of Applied Health Sciences, University of Waterloo [Waterloo], Service de physiologie, Université de Brest (UBO), Senhadji, Lotfi
Jazyk: angličtina
Rok vydání: 2009
Předmět:
Zdroj: European Journal of Applied Physiology
European Journal of Applied Physiology, 2009, 106 (2), pp.217-27. ⟨10.1007/s00421-009-1009-6⟩
ISSN: 1439-6319
1439-6327
DOI: 10.1007/s00421-009-1009-6⟩
Popis: International audience; Cardiovascular deconditioning after long duration spaceflight is especially challenging in women who have a lower orthostatic tolerance (OT) compared with men. We hypothesized that an exercise prescription, combining supine aerobic treadmill exercise in a lower body negative pressure (LBNP) chamber followed by 10 min of resting LBNP, three to four times a week, and flywheel resistive training every third day would maintain orthostatic tolerance (OT) in women during a 60-day head-down-tilt bed rest (HDBR). Sixteen women were assigned to two groups (exercise, control). Pre and post HDBR OT was assessed with a tilt/LBNP test until presyncope. OT time (mean +/- SE) decreased from 17.5 +/- 1.0 min to 9.1 +/- 1.5 min (-50 +/- 6%) in control group (P < 0.001) and from 19.3 +/- 1.3 min to 13.0 +/- 1.9 min (-35 +/- 7%) in exercise group (P < 0.001), with no significant difference in OT time between the two groups after HDBR (P = 0.13). Nevertheless, compared with controls post HDBR, exercisers had a lower heart rate during supine rest (mean +/- SE, 71 +/- 3 vs. 85 +/- 4, P < 0.01), a slower increase in heart rate and a slower decrease in stroke volume over the course of tilt/LBNP test (P < 0.05). Blood volume (mean +/- SE) decreased in controls (-9 +/- 2%, P < 0.01) but was maintained in exercisers (-4 +/- 3%, P = 0.17).Our results suggest that the combined exercise countermeasure did not significantly improve OT but protected blood volume and cardiovascular response to sub tolerance levels of orthostatic stress.
Databáze: OpenAIRE
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