The influence of acute hypoxic exposure on isokinetic muscle force production

To investigated whether an acute hypoxic stimulus affects muscle strength development assessed by isokinetic dynamometry during maximal knee extension. A total of 15 healthy young men participated in this study (61.9 ± 6.1 kg; 1.72 ± 0.08 m; 20.9 ± 2.6 years). We evaluated knee extension and flexion...

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Bibliographic Details
Published in:	SpringerPlus Vol. 3; no. 1; p. 604
Main Authors:	Ivamoto, Rafael Kenji, Nakamoto, Fernanda Patti, Vancini, Rodrigo Luiz, Benedito-Silva, Ana Amélia, de Lira, Claudio Andre Barbosa, Andrade, Marília dos Santos
Format:	Journal Article
Language:	English
Published:	Cham Springer International Publishing 15-10-2014 Springer Nature B.V BioMed Central Ltd
Subjects:	Biomedical and Life Sciences Humanities and Social Sciences multidisciplinary Science Science (multidisciplinary) Isokinetic dynamometry Normoxia Knee muscle strength Oxygen saturation
Online Access:	Get full text
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Summary:	To investigated whether an acute hypoxic stimulus affects muscle strength development assessed by isokinetic dynamometry during maximal knee extension. A total of 15 healthy young men participated in this study (61.9 ± 6.1 kg; 1.72 ± 0.08 m; 20.9 ± 2.6 years). We evaluated knee extension and flexion isokinetic dynamometer performance in normoxic and hypoxic conditions. The analyzed parameters, for concentric contraction, were peak torque and total work measured at 1.05 and 5.23 rad/s; and fatigue index measured at 5.23 rad/s. During isokinetic testing, heart rate and oxygen saturation (SpO 2 ) were monitored. Hypoxic conditions (3,600 m) were simulated, via a mixing chamber, with the dilution being constantly controlled by a PO 2 probe. Test reproducibility results (test-retest) for all isokinetic knee parameters were classified as moderate to almost perfect (ICC = 0.694 to 0.932). SpO 2 was 88.4 ± 3.4% in the hypoxic condition and 97.1 ± 0.7% in the normoxic condition (p = 0.000, effect size = 0.87). Heart rate was not significantly different between normoxic and hypoxic conditions at the end of the test. There were no significant differences in isokinetic variables evaluated for the extensor and flexor muscles at concentric contraction between the normoxic and hypoxic conditions. Our findings indicate that reduced arterial oxygenation per se has no effect on the muscular isokinetic strength of the knee extensors.
Bibliography:	ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23
ISSN:	2193-1801 2193-1801
DOI:	10.1186/2193-1801-3-604