Abstract

Ventilation per minute (VE) and percent fractional expired oxygen (FEO2()) data were used to determine the work rate at which the ventilatory threshold occurred during an incremental kayak test. Although an exponential curve fitted the ventilation data significantly, a quartic curve was more useful for subjective determination of the ventilatory threshold. A cubic polynomial curve fitted the blood lactate, pH, carbon dioxide pressure, bicarbonate, and base-excess data from an incremental test on a treadmill, indicating the more complex curvilinear nature of these parameters as exercise intensity increased. This creates difficulties for the objective determination of a training intensity, which is likely to induce optimal training adaptation. In addition, the prescription of training based on a set blood lactate concentration may result in different physiologic stress for different individuals. Heart rate was found to vary little within a range of work rates that induced maximum variation in lactate concentration, creating difficulties in using heart rate to monitor work intensity at higher work rates. Lactate concentration was found to be protocol specific and independent of work rate. Lactate concentration at an equivalent work rate in two different protocols was significantly different. Verf.-Referat