Kinetics of Pulmonary Ventilation and Carbon Dioxide Output during Intermittent Increasing Cycling Exercise after a Prior Anaerobic Load

Background. Research aim was to establish the influence of a prior anaerobic load on the kinetics of ventilation (VE) and carbon dioxide output (VCO2) during onand off-transition phases of intermittent increasing cycling exercise. Methods. The seven healthy, physically active females volunteered to estimate the influence of a prior anaerobic load on the kinetics of respiratory parameters. During the first visit VO2max was evaluated using the increasing cycling exercise test. During the second testing the participants performed intermittent cycling exercise (ICE). During the other visit they performed supramaximal 30 s anaerobic exercise and after 15 min of the rest – ICE. In order to estimate the kinetics of respiratory parameters were analysed by adopting mono-exponential function. Results. Mean blood lactate concentration was increased during ICE performed after prior anaerobic load in the presence of a residual metabolic acidosis. The asymptote and amplitude of monoexponential function reflecting VCO2 kinetics during onand off-transitions were not changed after prior anaerobic load. The time constant of this function was significantly longer (p < .01) both during onand off-transitions at work rate below lactate threshold (LT), whereas this parameter at higher work intensities remained unchanged. The parameters of VE monoexponential function during onand off-transitions were not changed after prior anaerobic load. Conclusion. Despite similar physiological mechanism responsible for VE and CO2 regulation during exercise the prior anaerobic load had different influence on the ventilation and VCO2 kinetics during exercise below lactate threshold causing slowing of VCO2 without changes of VE kinetics.