Artificial gravity with ergometric exercise as a countermeasure against cardiovascular deconditioning during 4 days of head-down bed rest in humans.

Autor:	Yong-Chun Wang, Chang-Bin Yang, Yan-Hong Wu, Yuan Gao, Dong-Yuan Lu, Fei Shi, Xiao-Ming Wei, Xi-Qing Sun, Wang, Yong-Chun, Yang, Chang-Bin, Wu, Yan-Hong, Gao, Yuan, Lu, Dong-Yuan, Shi, Fei, Wei, Xiao-Ming, Sun, Xi-Qing
Předmět:	ARTIFICIAL gravity BED rest BLOOD pressure HEMODYNAMICS SPECTRAL analysis (Phonetics) BODY weight COMPARATIVE studies EXERCISE EXERCISE tests HEART beat RESEARCH methodology MEDICAL cooperation RESEARCH TIME WEIGHTLESSNESS CARDIOVASCULAR fitness EVALUATION research RANDOMIZED controlled trials HEAD-down tilt position
Zdroj:	European Journal of Applied Physiology; Aug2011, Vol. 111 Issue 9, p2315-2325, 11p, 1 Black and White Photograph, 2 Charts, 5 Graphs
Abstrakt:	We have shown previously that combined short-arm centrifuge and aerobic exercise training preserved several physiologically important cardiovascular functions in humans. We hypothesized that artificial gravity (AG) and exercise is effective to prevent changes of physical problems during head-down bed rest (HDBR). To test this hypothesis, 12 healthy male subjects had undergone 4 days of 6° HDBR. Six of them were exposed to AG of an alternating 2-min intervals of +1.0 and +2.0 Gz at foot level for 30 min twice per day with ergometric exercise of 40 W as a countermeasure during bed rest (CM group), while the remaining six served as untreated controls (no-CM group). Before and after 4 days of bed rest, leg venous hemodynamics was assessed by venous occlusion plethysmography and autonomic cardiovascular control estimated by power spectral analysis of blood pressure and heart rate. Further, orthostatic tolerance was evaluated by a 75° head-up tilt test and physical working capacity was surveyed by near maximal physical working capacity test before and after bed rest. The data showed that combined centrifuge and exercise applied twice daily for a total of 60 min during 4 days of HDBR prevented (a) a decrease in working capacity, (b) autonomic dysfunction (a decrease in the activity of parasympathetic cardiac innervation) and (c) an increase in leg venous flow resistance. The combination of a 30 min alternating of +1.0 and +2.0 Gz for twice per day of AG with 40 W ergometric exercise may offer a promising countermeasure to short duration simulated microgravity. [ABSTRACT FROM AUTHOR]
Databáze:	Complementary Index
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