Consequences of exercise-induced respiratory muscle work.
We briefly review the evidence for a hypothesis, which links the ventilatory response to heavy intensity, sustained exercise-to-exercise performance limitation in health. A key step in this linkage is a respiratory muscle fatigue-induced metaboreflex, which increases sympathetic vasoconstrictor outflow, causing reduced blood flow to locomotor muscles and locomotor muscle fatigue. In turn, the limb fatigue comprises an important dual contribution to both peripheral and central fatigue mechanisms, which contribute to limiting exercise performance. Clinical implications for respiratory limitations to exercise in patients with chronic obstructive lung disease (COPD) and chronic heart failure (CHF) are discussed and key unresolved problems are outlined.
Dempsey
Jerome A
JA
John Rankin Laboratory of Pulmonary Medicine, Department of Population Health Sciences, University of Wisconsin, Madison, WI 53706, USA. jdempsey@wisc.edu
Romer
Lee
L
Rodman
Joshua
J
Miller
Jordan
J
Smith
Curtis
C
D000818:Animals; D015444:Exercise / Q000502:physiology*; D006801:Humans; D008954:Models, Biological; D018763:Muscle Fatigue / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology*; D012132:Respiratory Muscles / Q000502:physiology*