Energy expenditure during antiorthostatic bed rest (simulated microgravity)
نویسندگان
چکیده
منابع مشابه
Energy expenditure during antiorthostatic bed rest (simulated microgravity).
Few studies have addressed the interaction between energy balance and lean body mass in healthy subjects during spaceflight or its simulations. We used doubly labeled water to measure total energy expenditure (TEE) in nine healthy adult men during two 7-day periods, once before and once during a 10-day head-down bed-rest period. Mean TEE was 21% less during than before bed rest; however, neithe...
متن کاملIncrease in epinephrine-induced responsiveness during microgravity simulated by head-down bed rest in humans.
The epinephrine (Epi)-induced effects on the sympathetic nervous system (SNS) and metabolic functions were studied in men before and during a decrease in SNS activity achieved through simulated microgravity. Epi was infused at 3 graded rates (0.01, 0.02, and 0. 03 microg. kg(-1). min(-1) for 40 min each) before and on the fifth day of head-down bed rest (HDBR). The effects of Epi on the SNS (as...
متن کاملEnergy Expenditure at Rest and During Exercise
The immediate source for muscle contraction is delivered from splitting of adenosine triphosphate (ATP) to adenosine diphosphate (ADP) and a ‘free’ phosphate ion (P). This reaction is very fast and does not normally limit energy turnover andmuscle performance. However, the ATP stores in the muscles are very limited. The whole ATP pool would be emptied in only a few seconds of muscle contraction...
متن کاملSympathetic nervous activity decreases during head-down bed rest but not during microgravity.
We tested the hypothesis that sympathoadrenal activity in humans is low during spaceflight and that this effect can be simulated by head-down bed rest (HDBR). Platelet norepinephrine and epinephrine were measured as indexes of long-term changes in sympathoadrenal activity. Ten normal healthy subjects were studied before and during HDBR of 2-wk duration, as well as during an ambulatory study per...
متن کاملLong-duration bed rest as an analog to microgravity.
Long-duration bed rest is widely employed to simulate the effects of microgravity on various physiological systems, especially for studies of bone, muscle, and the cardiovascular system. This microgravity analog is also extensively used to develop and test countermeasures to microgravity-altered adaptations to Earth gravity. Initial investigations of bone loss used horizontal bed rest with the ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Applied Physiology
سال: 1995
ISSN: 8750-7587,1522-1601
DOI: 10.1152/jappl.1995.78.6.2207