HRV measurement and analysis. A commercially available heart rate monitor (Suunto watch, model T6, FitzWright Company Ltd., Langley, BC, Canada) was used. The data recordings obtained from the heart rate monitor were analyzed for a five minute interval starting at the 80 Hz mark, in order to eliminate "bruit" from the initial positioning of the subject on the table, finishing at the 380 Hz mark,. The analysis was performed with a personal computer using custom software 15 (Kubios, Biosignal Analysis and Medical Imaging Group, Department of Physics, University of Kuopio, Kuopio, Finland) for several HRV parameters, as described below. As well, as mentioned above, there were no attempts to blind the assessment since the data were recorded directly into the heart rate monitor. Thus, the examiner could not know the value during measurement. The risk of influencing HRV was kept to a minimum by insuring that the interaction, between the subject and the examiner, limited itself to the installation and removal of the recording apparatus.