The precision of extimating the total energy demand: Implications for the determination of the accumulated oxygen deficit

This study observed the precision of estimating the total energy demand required to calculate the AOD using three different VO₂ - power regressions which included, five VO₂ - power regression points and a forced y-intercept of 5.1 ml/kg/min (5+Y) (1), five VO₂ - power regression points without a forced y-intercept of 5.1 ml/kg/min (5-Y), Medbø's "procedure 3" (MED) (1). Fourteen well-trained schoolboy rowers completed a 2000-m performance test, VO₂peak test, five submaximal tests, and an exhaustive 2-min test using rowing ergometry. There were no differences between the estimated total energy demand (ETED), AOD and slope of the regression lines when established from either of the three regression equations. The regressions developed from methods 5+Y and MED reduced the length of the 95% confidence interval (95% CI) (p<0.0167) compared to the method 5-Y. 2000-m rowing ergometer performance was significantly predicted by VO₂peak and the AOD determined by either of methods 5+Y (p = 0.047) and MED (p = 0.042). The inclusion of a y-intercept value when estimating the total energy demand with a reduced number of regression points reduces the length of the 95% CI, increases the precision of the estimated value and therefore reduces the variability of the AOD measurement. It is suggested that the length of the 95% CI of the ETED be used as a criteria to measure the degree of precision in the estimated value. This approach has potential for improving the reproducibility of the AOD.