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Effects of Acute Hypoxia on the Estimation of the Lactate Threshold from Ventilatory Gas Exchange Indices During an Incremental Exercise Test      
Yazarlar
Prof. Dr. Oğuz ÖZÇELİK Prof. Dr. Oğuz ÖZÇELİK
Kastamonu Üniversitesi, Türkiye
H. Kelestimur
Firat Üniversitesi, Turkey
Özet
The purpose of this study was to investigate the validity of non-invasive lactate threshold estimation using ventilatory and pulmonary gas exchange indices under condition of acute hypoxia. Seven untrained males (21.4±1.2 years) performed two incremental exercise tests using an electromagnetically braked cycle ergometer: one breathing room air and other breathing 12% O 2. The lactate threshold was estimated using the following parameters: increase of ventilatory equivalent for O2 (V E/VO2) without increase of ventilatory equivalent for CO2 (VE/VCO2). It was also determined from the increase in blood lactate and decrease in standard bicarbonate. The V E/VO2 and lactate increase methods yielded the respective values for lactate threshold: 1.91±0.10 l/mi n (for the V E/VO2) vs. 1.89±0.1 l/min (for the lactate). However, in hypoxic condition, VE/VO2 started to increase prior to the actual threshold as determined from blood lactate response: 1.67±0.1 l/min (for the lactate) vs. 1.37±0.09 l/min (for the VE/VO2) (P=0.0001), i.e. resulted in pseudo-threshold behavior. In conclusion, the ventilatory and gas exchange indices provide an accurate lactate threshold. Although the potential for pseudo-threshold behavior of the standard ventilatory and gas exchange indices of the lactate threshold must be concerned if an incremental test is performed under hypoxic conditions in which carotid body chemosensitivity is increased.
Anahtar Kelimeler
Exercise | Hypoxia | Lactate threshold
Makale Türü Özgün Makale
Makale Alt Türü SSCI, AHCI, SCI, SCI-Exp dergilerinde yayımlanan tam makale
Dergi Adı Physiol. Res
Dergi ISSN 0862-8408
Dergi Tarandığı Indeksler SSCI
Makale Dili İngilizce
Basım Tarihi 01-2004
Cilt No 53
Sayı 6
Sayfalar 653 / 659
BM Sürdürülebilir Kalkınma Amaçları
Atıf Sayıları
SCOPUS 16
Google Scholar 40

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