Hypoxic effects on exercise-induced diaphragmatic fatigue in normal healthy humans

M. A. Babcock, B. D. Johnson, D. F. Pegelow, Oscar Suman, D. Griffin, J. A. Dempsey

Research output: Contribution to journalArticle

69 Citations (Scopus)

Abstract

We examined the effects of hypoxia on exercise-induced diaphragmatic fatigue. Eleven subjects with a mean maximal O2 uptake of 52.4 ± 0.7 ml. kg-1 · min-1 completed one normoxic (arterial O2 saturation 96-94%) and one hypoxic (inspiratory O2 fraction = 0.15; arterial O2 saturation 83- 77%) exercise test at 85% maximal O2 uptake to exhaustion on separate days. Supramaximal bilateral phrenic nerve stimulation (BPNS) was used to determine the pressure generation of the diaphragm pre- and postexercise at 1, 10, and 20 Hz. There was increased flow limitation during hypoxic vs. normoxic exercise. There was a decrease in hypoxic exercise time (normoxic 24.9 ± 0.7 min vs. hypoxic 15.8 ± 0.8 min; P < 0.05). After exercise the BPNS transdiaphragmatic pressure (Pdi) was significantly reduced at 1 and 10 Hz after both exercise tests. The BPNS Pdi was recovered to control values by 60 min postnormoxic exercise but was still reduced 90 min posthypoxic exercise. The mean percent fall in the stimulated BPNS Pdi was similar (normoxic -24.8 ± 4.7%; hypoxic -18.8 ± 3.0%) after both exercise conditions. Experiencing the same amount of diaphragm fatigue in a shorter time period in hypoxic exercise may have been due to 1) the increased expiratory flow limitation and diaphragmatic muscle work, 2) decreased O2 transport to the diaphragm, and/or 3) increased levels of circulating metabolites.

Original languageEnglish (US)
Pages (from-to)82-92
Number of pages11
JournalJournal of Applied Physiology
Volume78
Issue number1
StatePublished - 1995
Externally publishedYes

Fingerprint

Phrenic Nerve
Diaphragm
Fatigue
Exercise Test
Pressure

Keywords

  • endurance exercise
  • low-frequency fatigue
  • transdiaphragmatic pressure

ASJC Scopus subject areas

  • Endocrinology
  • Physiology
  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation

Cite this

Babcock, M. A., Johnson, B. D., Pegelow, D. F., Suman, O., Griffin, D., & Dempsey, J. A. (1995). Hypoxic effects on exercise-induced diaphragmatic fatigue in normal healthy humans. Journal of Applied Physiology, 78(1), 82-92.

Hypoxic effects on exercise-induced diaphragmatic fatigue in normal healthy humans. / Babcock, M. A.; Johnson, B. D.; Pegelow, D. F.; Suman, Oscar; Griffin, D.; Dempsey, J. A.

In: Journal of Applied Physiology, Vol. 78, No. 1, 1995, p. 82-92.

Research output: Contribution to journalArticle

Babcock, MA, Johnson, BD, Pegelow, DF, Suman, O, Griffin, D & Dempsey, JA 1995, 'Hypoxic effects on exercise-induced diaphragmatic fatigue in normal healthy humans', Journal of Applied Physiology, vol. 78, no. 1, pp. 82-92.
Babcock MA, Johnson BD, Pegelow DF, Suman O, Griffin D, Dempsey JA. Hypoxic effects on exercise-induced diaphragmatic fatigue in normal healthy humans. Journal of Applied Physiology. 1995;78(1):82-92.
Babcock, M. A. ; Johnson, B. D. ; Pegelow, D. F. ; Suman, Oscar ; Griffin, D. ; Dempsey, J. A. / Hypoxic effects on exercise-induced diaphragmatic fatigue in normal healthy humans. In: Journal of Applied Physiology. 1995 ; Vol. 78, No. 1. pp. 82-92.
@article{30913ce3eb924c7fade794ee7429a76b,
title = "Hypoxic effects on exercise-induced diaphragmatic fatigue in normal healthy humans",
abstract = "We examined the effects of hypoxia on exercise-induced diaphragmatic fatigue. Eleven subjects with a mean maximal O2 uptake of 52.4 ± 0.7 ml. kg-1 · min-1 completed one normoxic (arterial O2 saturation 96-94{\%}) and one hypoxic (inspiratory O2 fraction = 0.15; arterial O2 saturation 83- 77{\%}) exercise test at 85{\%} maximal O2 uptake to exhaustion on separate days. Supramaximal bilateral phrenic nerve stimulation (BPNS) was used to determine the pressure generation of the diaphragm pre- and postexercise at 1, 10, and 20 Hz. There was increased flow limitation during hypoxic vs. normoxic exercise. There was a decrease in hypoxic exercise time (normoxic 24.9 ± 0.7 min vs. hypoxic 15.8 ± 0.8 min; P < 0.05). After exercise the BPNS transdiaphragmatic pressure (Pdi) was significantly reduced at 1 and 10 Hz after both exercise tests. The BPNS Pdi was recovered to control values by 60 min postnormoxic exercise but was still reduced 90 min posthypoxic exercise. The mean percent fall in the stimulated BPNS Pdi was similar (normoxic -24.8 ± 4.7{\%}; hypoxic -18.8 ± 3.0{\%}) after both exercise conditions. Experiencing the same amount of diaphragm fatigue in a shorter time period in hypoxic exercise may have been due to 1) the increased expiratory flow limitation and diaphragmatic muscle work, 2) decreased O2 transport to the diaphragm, and/or 3) increased levels of circulating metabolites.",
keywords = "endurance exercise, low-frequency fatigue, transdiaphragmatic pressure",
author = "Babcock, {M. A.} and Johnson, {B. D.} and Pegelow, {D. F.} and Oscar Suman and D. Griffin and Dempsey, {J. A.}",
year = "1995",
language = "English (US)",
volume = "78",
pages = "82--92",
journal = "Journal of Applied Physiology",
issn = "8750-7587",
publisher = "American Physiological Society",
number = "1",

}

TY - JOUR

T1 - Hypoxic effects on exercise-induced diaphragmatic fatigue in normal healthy humans

AU - Babcock, M. A.

AU - Johnson, B. D.

AU - Pegelow, D. F.

AU - Suman, Oscar

AU - Griffin, D.

AU - Dempsey, J. A.

PY - 1995

Y1 - 1995

N2 - We examined the effects of hypoxia on exercise-induced diaphragmatic fatigue. Eleven subjects with a mean maximal O2 uptake of 52.4 ± 0.7 ml. kg-1 · min-1 completed one normoxic (arterial O2 saturation 96-94%) and one hypoxic (inspiratory O2 fraction = 0.15; arterial O2 saturation 83- 77%) exercise test at 85% maximal O2 uptake to exhaustion on separate days. Supramaximal bilateral phrenic nerve stimulation (BPNS) was used to determine the pressure generation of the diaphragm pre- and postexercise at 1, 10, and 20 Hz. There was increased flow limitation during hypoxic vs. normoxic exercise. There was a decrease in hypoxic exercise time (normoxic 24.9 ± 0.7 min vs. hypoxic 15.8 ± 0.8 min; P < 0.05). After exercise the BPNS transdiaphragmatic pressure (Pdi) was significantly reduced at 1 and 10 Hz after both exercise tests. The BPNS Pdi was recovered to control values by 60 min postnormoxic exercise but was still reduced 90 min posthypoxic exercise. The mean percent fall in the stimulated BPNS Pdi was similar (normoxic -24.8 ± 4.7%; hypoxic -18.8 ± 3.0%) after both exercise conditions. Experiencing the same amount of diaphragm fatigue in a shorter time period in hypoxic exercise may have been due to 1) the increased expiratory flow limitation and diaphragmatic muscle work, 2) decreased O2 transport to the diaphragm, and/or 3) increased levels of circulating metabolites.

AB - We examined the effects of hypoxia on exercise-induced diaphragmatic fatigue. Eleven subjects with a mean maximal O2 uptake of 52.4 ± 0.7 ml. kg-1 · min-1 completed one normoxic (arterial O2 saturation 96-94%) and one hypoxic (inspiratory O2 fraction = 0.15; arterial O2 saturation 83- 77%) exercise test at 85% maximal O2 uptake to exhaustion on separate days. Supramaximal bilateral phrenic nerve stimulation (BPNS) was used to determine the pressure generation of the diaphragm pre- and postexercise at 1, 10, and 20 Hz. There was increased flow limitation during hypoxic vs. normoxic exercise. There was a decrease in hypoxic exercise time (normoxic 24.9 ± 0.7 min vs. hypoxic 15.8 ± 0.8 min; P < 0.05). After exercise the BPNS transdiaphragmatic pressure (Pdi) was significantly reduced at 1 and 10 Hz after both exercise tests. The BPNS Pdi was recovered to control values by 60 min postnormoxic exercise but was still reduced 90 min posthypoxic exercise. The mean percent fall in the stimulated BPNS Pdi was similar (normoxic -24.8 ± 4.7%; hypoxic -18.8 ± 3.0%) after both exercise conditions. Experiencing the same amount of diaphragm fatigue in a shorter time period in hypoxic exercise may have been due to 1) the increased expiratory flow limitation and diaphragmatic muscle work, 2) decreased O2 transport to the diaphragm, and/or 3) increased levels of circulating metabolites.

KW - endurance exercise

KW - low-frequency fatigue

KW - transdiaphragmatic pressure

UR - http://www.scopus.com/inward/record.url?scp=0028795655&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028795655&partnerID=8YFLogxK

M3 - Article

VL - 78

SP - 82

EP - 92

JO - Journal of Applied Physiology

JF - Journal of Applied Physiology

SN - 8750-7587

IS - 1

ER -