| Frontal and motor cortex oxygenation during maximal exercise in normoxia and hypoxia. | |
| | |
MedLine Citation:
|
PMID: 19150853 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Reductions in prefrontal oxygenation near maximal exertion may limit exercise performance by impairing executive functions that influence the decision to stop exercising; however, whether deoxygenation also occurs in motor regions that more directly affect central motor drive is unknown. Multichannel near-infrared spectroscopy was used to compare changes in prefrontal, premotor, and motor cortices during exhaustive exercise. Twenty-three subjects performed two sequential, incremental cycle tests (25 W/min ramp) during acute hypoxia [79 Torr inspired Po(2) (Pi(O(2)))] and normoxia (117 Torr Pi(O(2))) in an environmental chamber. Test order was balanced, and subjects were blinded to chamber pressure. In normoxia, bilateral prefrontal oxygenation was maintained during low- and moderate-intensity exercise but dropped 9.0 +/- 10.7% (mean +/- SD, P < 0.05) before exhaustion (maximal power = 305 +/- 52 W). The pattern and magnitude of deoxygenation were similar in prefrontal, premotor, and motor regions (R(2) > 0.94). In hypoxia, prefrontal oxygenation was reduced 11.1 +/- 14.3% at rest (P < 0.01) and fell another 26.5 +/- 19.5% (P < 0.01) at exhaustion (maximal power = 256 +/- 38 W, P < 0.01). Correlations between regions were high (R(2) > 0.61), but deoxygenation was greater in prefrontal than premotor and motor regions (P < 0.05). Prefrontal, premotor, and motor cortex deoxygenation during high-intensity exercise may contribute to an integrative decision to stop exercise. The accelerated rate of cortical deoxygenation in hypoxia may hasten this effect. |
| | |
Authors:
|
Andrew W Subudhi; Brittany R Miramon; Matthew E Granger; Robert C Roach |
Related Documents
:
|
17072063 - Ventilatory augmentation by acute intermittent hypoxia in the rabbit. 1212553 - Blood gases in simple coal workers' pneumoconiosis. 902653 - A comparison of three w170 protocols. |
Publication Detail:
|
Type: Journal Article; Research Support, N.I.H., Extramural Date: 2009-01-15 |
Journal Detail:
|
Title: Journal of applied physiology (Bethesda, Md. : 1985) Volume: 106 ISSN: 8750-7587 ISO Abbreviation: J. Appl. Physiol. Publication Date: 2009 Apr |
Date Detail:
|
Created Date: 2009-04-01 Completed Date: 2009-05-29 Revised Date: 2010-09-23 |
Medline Journal Info:
|
Nlm Unique ID: 8502536 Medline TA: J Appl Physiol Country: United States |
Other Details:
|
Languages: eng Pagination: 1153-8 Citation Subset: IM |
Affiliation:
|
University of Colorado Altitude Research Center, Denver and Colorado Springs Campuses, Colorado Springs, CO 80918, USA. asubudhi@uccs.edu |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adult Anaerobic Threshold / physiology Anoxia / physiopathology* Carbon Dioxide / blood Cerebrovascular Circulation / physiology Exercise / physiology* Exercise Test Female Humans Male Motor Cortex / physiology*, physiopathology Oxygen Consumption / physiology* Prefrontal Cortex / physiology*, physiopathology Spectroscopy, Near-Infrared Ultrasonography, Doppler, Transcranial |
| Grant Support | |
ID/Acronym/Agency:
|
HL-070362/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
|
124-38-9/Carbon Dioxide |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Exercise in space: human skeletal muscle after 6 months aboard the International Space Station.
Next Document: Estimation of critical torque using intermittent isometric maximal voluntary contractions of the qua...