Task Hypovolemia as A Model Of Space Flight: Cardiovascular Exercise Effects and Countermeasures (Completed)
Last Published:  03/26/21 03:34:00 PM (Central)
Short Title: Hypo/VO2 add on
Responsible HRP Element: Human Health Countermeasures
Collaborating Org(s):
Funding Status: Completed - Task completed and produced a deliverable
Procurement Mechanism(s):
Directed
Aims:

Reduced exercise capacity, orthostatic tolerance, and plasma volume are common observances following space flight and bed rest.

The specific aims of this study are to:

1.)     Understand the contribution of hypovolemia to space flight-induced changes in aerobic capacity.

2.)     Determine effect of hypovolemia on cardiac function during exercise.

3.)     Examine changes in skeletal muscle metabolism during exercise and hypovolemia using non-invasive near infrared spectroscopy.

The Johnson Space Center Cardiovascular Laboratory will investigate the relationship between orthostatic hypotension and plasma volume by pharmacologically inducing hypovolemia in 48 normal subjects. The Exercise Physiology and Countermeasures (ExPC) Project and the Cardiovascular Discipline seek to extend this information to understanding the factors involved in decreased exercise capacity. Following orthostatic testing in normal and hypovolemic conditions, subjects recruited by the Cardiovascular Laboratory team may volunteer to perform a graded cycle exercise test to volitional fatigue to determine peak oxygen consumption (VO2pk). Oxygen consumption, heart rate, rating of perceived exertion, and blood pressure will be measured per standard laboratory protocols. Additionally, echocardiographic measures of stroke volume, systolic and diastolic function, blood lactate, plasma catecholamines, and peripheral muscle metabolism by near infrared spectroscopy will be measured. Data from these testing sessions will assist in understanding of the factors associated with reduced exercise capacity after space flight; will serve as a basis of comparison for responses to similar tests after space flight and bed rest; and will aid in the continued development of near infrared spectroscopy as a noninvasive metabolic measurement system for space flight and extravehicular activities.

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RiskRisk of Reduced Physical Performance Capabilities Due to Reduced Aerobic Capacity
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