Expiratory muscle loading increases intercostal muscle blood flow during leg exercise in healthy humans

Dimitris Athanasopoulos, Zafeiris Louvaris, Evgenia Cherouveim, Vasilis Andrianopoulos, Charis Roussos, Spyros Zakynthinos, I Vogiatzis

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

We investigated whether expiratory muscle loading induced by the application of expiratory flow limitation (EFL) during exercise in healthy subjects causes a reduction in quadriceps muscle blood flow in favor of the blood flow to the intercostal muscles. We hypothesized that, during exercise with EFL quadriceps muscle blood flow would be reduced, whereas intercostal muscle blood flow would be increased compared with exercise without EFL. We initially performed an incremental exercise test on eight healthy male subjects with a Starling resistor in the expiratory line limiting expiratory flow to similar to 1 l/s to determine peak EFL exercise workload. On a different day, two constant-load exercise trials were performed in a balanced ordering sequence, during which subjects exercised with or without EFL at peak EFL exercise workload for 6 min. Intercostal (probe over the 7th intercostal space) and vastus lateralis muscle blood flow index (BFI) was calculated by near-infrared spectroscopy using indocyanine green, whereas cardiac output (CO) was measured by an impedance cardiography technique. At exercise termination, CO and stroke volume were not significantly different during exercise, with or without EFL (CO: 16.5 vs. 15.2 l/min, stroke volume: 104 vs. 107 ml/beat). Quadriceps muscle BFI during exercise with EFL (5.4 nM/s) was significantly (P = 0.043) lower compared with exercise without EFL (7.6 nM/s), whereas intercostal muscle BFI during exercise with EFL (3.5 nM/s) was significantly (P = 0.021) greater compared with that recorded during control exercise (0.4 nM/s). In conclusion, increased respiratory muscle loading during exercise in healthy humans causes an increase in blood flow to the intercostal muscles and a concomitant decrease in quadriceps muscle blood flow.
Original languageEnglish
Pages (from-to)388-395
Number of pages8
JournalJournal of Applied Physiology
Volume109
Issue number2
DOIs
Publication statusPublished - Aug 2010
Externally publishedYes

Keywords

  • expiratory flow limitation
  • quadriceps muscle blood flow
  • near-infrared spectrometry

Cite this

Athanasopoulos, D., Louvaris, Z., Cherouveim, E., Andrianopoulos, V., Roussos, C., Zakynthinos, S., & Vogiatzis, I. (2010). Expiratory muscle loading increases intercostal muscle blood flow during leg exercise in healthy humans. Journal of Applied Physiology, 109(2), 388-395. https://doi.org/10.1152/japplphysiol.01290.2009