Effects of rider position on continuous wave Doppler responses to maximal cycle ergometry

Using 10 well-trained (VO2peak = 60.6 ml kg-1min-1) college age cyclists and continuous wave Doppler echocardiography, peak acceleration (PkA) and velocity (PkV) of blood flow in the ascending aorta, and the stroke velocity integral (SVI) were assessed to determine if rider position influenced the central haemodynamic responses to graded maximal cycle ergometry. Cyclist position was determined by hand placement on the uprights (UPRI) or drops (DROP) of conventional handlebars or using aerodynamic handlebars (AHB). All subjects consistently achieved a peak workload of 300 W. The Doppler variables did not differ significantly between rider positions at each stage of the maximal exercise tests but did change in response to increasing workloads. PkA was significantly (P < 0.05) greater at workloads > or = 240 W versus < or = 120 W. PkV increased significantly (P < 0.05) up to 180 W and then reached a plateau. SVI increased to a workload of 120 W and then progressively declined, becoming significantly (P < 0.05) less at 300 W. For each stage, neither submaximal VO2, VI nor heart rate (HR) differed significantly between each trial. These results suggest that rider position does not affect the physiological response to maximal bicycle ergometry as responses to each position are similar.