Maximum oxygen uptake (Vo₂max) is generally considered the most accurate measure of cardiovascular endurance. The most precise evaluation of Vo₂max is performed setting with a subject involving a maximal graded exercise either on treadmill or bicycle ergometer until exhaustion while applying analysis of expired gas. This requires special equipments and technical skill, and is not only troublesome but also dangerous for some types of subjects. Toovercome the problems, numerous devices and techniques have been devised for evaluation of physical working capacity under submaximal exercise such as application of nomograms, PWC₁₇₀, etc.. Basing on the idea stating that certain kinds of physiological outputs during submaximal exercise at fixed work load should reflect cardiovascular endurance, authors confirmed through preliminary experiments that figures drawn by the combination of changes in systolic blood pressure and heart rates during short-period (2 minutes) and light-loaded (600 kpm/min) exercise showed clear distinction between trained and untrained subjects. This figure was named BP-HR Lissajous' figure.
　The purpose of this study was to develop a simpler and easier method for evaluation of cardiovascular endurance by analyzing BP-HR Lissajous' figure. This time a newly developed blood pressure monitoring apparatus, Finapres, which had been proved to be accurate and reliable by many investigators was utilized for drawing BP-HR Lissajous' figure during and affer 2 minutes exercises on a bicycle ergometer work loads of which were 300, 450 and 600 kpm/ min respectively. The data were fed into a personal computer, and the figure was drawn by feeding heart rate into X-axis and systolic blood pressure into Y-axis. The estimated values of Vo₂max obtained from multiple regression analysis of the parameters calculated from the figures on 12 healthy male subjects (19.8 ± 1.4 years old) were compared with their actual values of Vo₂max, and the results suggested that this simple and easy testing method might be useful and effective, at work load of 600 kpm/min, r=0.921 (P < 0.02) with standard error of estimate 2.75 ml/kg・min, in evaluation of cardiovascular endurance.

DESCENTE SPORTS SCIENCE Vol.15/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE