C-15J Free Communication/Poster Anaerobic Threshold
The determination of ventilatory threshold (Tvent) has proven useful in the assessment of training effectiveness. However, as yet, determination of Tvent has been restricted to the laboratory. Thus, we compared a novel ambulatory monitoring system that uses inductive plythesmography (LifeShirtTM, VivoMetrics, Inc., Ventura, CA) to Tvent determined by a standard mass flow device (Hector Engineering, Bloomington, IN).
Five subjects wore the LifeShirtTM (LS) during a graded exercise test to Vo2 max. During the test, metabolic activity was measured by open flow indirect calorimetry. Ventilation was monitored simultaneously by the mass flow device (MF) and LS. The exercise intensity (as indicated by Vco2) where Tvent occurred was determined by the V-slope method. Inter-device differences in Tvent values were tested within each subject by paired student's t-test (p < 0.05).
Exercise intensity where Tvent occurred did not differ between LS (Vco2 = 3.18 ± 0.70 L/min) and MF (Vco2 = 3.21 ± 0.66 L/min).
These data suggest the ambulatory technology (as employed by LifeShirtTM) can be used to characterize the ventilatory responses to exercise at different intensities.