Medicine and science in sports and exercise
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Med Sci Sports Exerc · Mar 1993
Relationship of oxygen consumption and cardiac output to work of breathing.
This study examined the relationship between work of breathing and estimated blood flow to and oxygen consumption by the respiratory muscles. Five subjects performed inspiratory loaded breathing and voluntary hyperpnea while ventilatory work, cardiac output, and oxygen consumption were measured. Blood flow to and oxygen consumption by the respiratory muscles were estimated by subtracting the resting from the working values of cardiac output the oxygen consumption, respectively. ⋯ During hyperpnea both cardiac output and oxygen consumption were correlated with work of breathing. Our results indicate that blood flow and oxygen consumption are increased in a regular pattern with increases in work of breathing. These results may be significant in estimating the demand of the respiratory muscles in disease and exercise.