Cardiorespiratory and vastus lateralis oxygenation-blood volume responses during incremental and modified Wingate tests

The purpose of this study was to compare the peak cardiorespiratory and muscle oxygenation-blood volume responses during 45 s and 60 s Wingate tests (Win45 and Win60 respectively) with those elicited during incremental cycle exercise to voluntary fatigue in healthy males. Nine volunteers (Mean +/- SD for age, height, body mass, and body mass index = 26.7 +/- 3.1 yrs, 176 +/- 6.5 cm, 77.8 +/- 10.9 kg, and 25.2 +/- 3.1 kg/m2, respectively) completed a cuff ischemia and stepwise incremental exercise test in session one, followed by the Win45 and Win60 tests (load factor = 75 g/kg body weight) in random order in subsequent sessions. Cardiorespiratory responses were monitored using a metabolic cart and heart rate monitor. Muscle oxygenation (Mox) and blood volume (Mbv) trends were continuously recorded simultaneously from the right vastus lateralis using dual wave length near infrared spectroscopy during all the tests. Analysis of variance indicated that the peak oxygen uptake (VO2), heart rate (HR), oxygen pulse (O-2 pulse) and ventilation rate (V-E) during the incremental and Win60 tests were significantly higher (p < 0.05) than the Win45 test, with no significant differences (p > 0.05) being observed between the incremental and Win60 tests. Blood lactate concentrations were not significantly different (p > 0.05) among the three tests. Mox was significantly lower (p < 0.05) during the incremental test compared to the Win45 and Win60 tests, while Mbv was significantly higher. Although peak values of VO2, heart rate and O-2 pulse were significantly correlated between the incremental and Win60 tests, Mox and Mbv were not significantly related (p > 0.05). Bland-Altman plots revealed that the peak cardiorespiratory responses during the Win60 test were within the limits of agreement for corresponding values attained on the incremental test. These results suggest that the Win60 test is a valid measure of the peak VO2 during cycle exercise in healthy males. However, the peripheral contribution that determines the peak VO2 during the Win60 and incremental tests is different. Relevance to Industry: To obtain valid measures of maximal oxygen uptake during exercise or physical work, it is common practice to test the participants' aerobic capacity using large muscle groups during treadmill running or cycling. Regardless of the exercise mode, the test protocol usually involves stepwise or ramp increments in the work rate at regular time intervals until volitional fatigue. Although this methodology is designed to maximally stress both the central and peripheral factors that determine the maximal oxygen uptake, these incremental tests are time consuming and do not clearly indicate the relative contribution of the aerobic and anaerobic energy components. The present study was designed to compare the whole body maximal oxygen uptake and localized skeletal muscle oxygenation during incremental and short duration high intensity exercise. (c) 2009 Elsevier B.V. All rights reserved.