| Autor: |
Zuccarelli, Lucrezia, do Nascimento Salvador, Paulo Cesar, Del Torto, Alessio, Fiorentino, Riccardo, Grassi, Bruno |
| Předmět: |
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| Zdroj: |
Journal of Applied Physiology; Mar2020, Vol. 128 Issue 3, p534-544, 11p |
| Abstrakt: |
Near-infrared spectroscopy (NIRS) has been utilized as a noninvasive method to evaluate skeletal muscle mitochondrial function in humans, by calculating muscle V O2 (V O2m) recovery (off-) kinetics following short light-intensity plantar flexion exercise. The aim of the present study was to determineV O2m off- kinetics following standard cycle ergometer exercise of different intensities. Fifteen young physically active healthy men performed an incremental exercise (INCR) up to exhaustion and two repetitions of constant work-rate (CWR) exercises at 80% of gas exchange threshold (GET; MODERATE) and at 40% of the difference between GET and peak pulmonary V O2 (V O2p; HEAVY). V O2p and vastus lateralis muscle fractional O2 extraction by NIRS [deoxy(HbMb)]) were recorded continuously. Transient arterial occlusions were carried out at rest and during the recovery for V O2m calculation. All subjects tolerated the repeated occlusions protocol without problems. The quality of the monoexponential fitting for V O2m off-kinetics analysis was excellent (0.93≤r2≤0.99). According to interclass correlation coefficient, the test-retest reliability was moderate to good. V O2m values at the onset of recovery were ~27, ~38, and ~35 times higher (in MODERATE, HEAVY, and INCR, respectively) than at rest. The time constants (τ) of V O2m off-kinetics were lower (P < 0.001) following MODERATE (29.1 ± 6.8 s) vs. HEAVY (40.8 ± 10.9) or INCR (42.9 ± 10.9), suggesting an exercise intensity dependency of V O2m off-kinetics. Only following MODERATE theV O2m off-kinetics were faster than the V O2p off-kinetics. V O2m off-kinetics, determined noninvasively by the NIRS repeated occlusions technique, can be utilized as a functional evaluation tool of skeletal muscle oxidative metabolism also following conventional cycle ergometer exercise. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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