Gas Exchange and Cardiovascular Kinetics of Regulation - Effects of Short Term Changes in Gravity

Overview

The regulation of the cardiovascular respiratory system after changing environmental conditions or changes in work rates are essential for cognitive as well as physical functioning. For decades, it is known that high level of headward acceleration (+Gz) impairs cardiovascular function that may cause loss of consciousness. Some "anti-g" maneuvers, such as muscle contraction of the lower extremities and buttocks or intermittent exhalation on exertion (i.e., exhalation against a closed airway) have been proved to increase tolerance to high +Gz. Main objective of this experiment is to investigate the effects of anti-g maneuvers on cardiovascular and respiratory tolerance to the push-pull-effect. Cardiovascular and respiratory functions will be evaluated with the following parameters: heart rate, stroke volume, cardiac output, blood pressure, oxygen uptake, carbon dioxide output, ventilation, breathing frequency, body core temperature. Electromyography (EMG) will not be a judgment criteria but will be used to check the quality of 'muscle contraction' anti-g maneuver. The main hypothesis is that anti-g maneuvers will increase cardiovascular and respiratory tolerance to the push-pull effect, especially when they are combined.

Conditions

Interventions