Our group worked and is currently working on cardiovascular adjustment at the onset of exercise. We have shown the changes in the baroreflex resetting in acute normobaric hypoxia in normal subjects (Lador F. et al, Am J Physiol 2008, Figure 2). The beat by beat data were obtained from the Modelflow method applied to pulse pressure profiles acquired from a Portapres (Finapres) device via the Beatscope software. Note that the data obtained by this method needs to be calibrated against a reference method if you want to improve accuracy for cardiac output determination (Tam E. et al, Clin Sci 2004 and Azabji M. et al. Clin Sci 2004). All the best. FL