Heart Rate as an Index of Oxygen Intake

Abstract

The purpose of this study is to investigate the relibaility and validity of prediction of the oxygen intake during works on the basis of heart rate at work.During four kinds of standard treadmill walking of 3.6km/h with a slope varying from o to 15 degrees and four kinds of standard bicycle ergometer work of o to 900kgm/min, the oxygen intake and heart rate were measured on four young adult males(Table1).For the whole subjects and for each individual, different regression equations of oxygen intake on heart rate were calculated from results of both types of work or from those of each typeof work.In addition, a new equation for prediction of oxygen intake from heart rate was proposed as_??_o2=vo2.(64.06HR-3086)/(0.6406hr-30.86)where _??_o2 is estimated value of oxygen intake during the work under investigation corresponding to _??_o2(oxygen intake during a given submaximal test work), HR(heart rate during the work under investigation), and hr(heart rate during the submaximal work).This new equation was made to be used fo radult males, on the basis of indirect determination of maximal oxygen intake from oxygen intake and heart rate during a submaximal work and a linear regression of %_??_o2max on heart rate.Estimated values of oxygen intake during the treadmill walking and ergometer work were computed using the above different regression equations and the new prediction and these values were compared with the directly determined values of oxygen intake during the work(Table 2).Although the best prediction was obtained in the case where the individual regression equations were applied to the same kinds of work as that for which the regression equations had been calculated, considerably high reliability of the new prediction equation which was made from our previous results in our laboratory were supported in this study.