Determination of Maximum Accumulated Oxygen Deficit Using Backward Extrapolation

This study aimed to compare the Maximum Accumulated Oxygen Deficit determined by the conventional method (MAOD_C) with that determined by the backward extrapolation technique (MAOD_EXTR) in runners. Fourteen runners underwent a maximal incremental test for determination of iVO_2MAX, ten submaximal efforts (50-95% of iVO_2MAX for 7 min). During the submaximal efforts oxygen consumption (VO₂) values were obtained conventionally and through the backward extrapolation technique (~ 3 s after the end of each effort). A supramaximal effort (110% of iVO_2MAX) (tLim_C) and five supramaximal bouts (tLim_EXTR) were performed. MAOD_C and MAOD_EXTR were determined from the difference between the VO₂ accumulated during tLim_C and tLim_EXTR and the predicted values. The tLim_C was lower than tLim_EXTR (164.06±36.32 s, 200.23±63.78 s, p<0.05). No significant differences were found between absolute and relative MAOD_C and MAOD_EXTR values, however, low intraclass correlations (0.26 and 0.24), high typical errors (2.03 L and 24 mL∙kg^-1) were observed, and coefficients of variation (46 and 48%), respectively. The graphical analysis of the differences showed agreement and correlation between the methods (r=0.86 and 0.85). Thus, it can be concluded that the MAOD_EXTR is not a valid method for estimating the anaerobic capacity of runners, moreover, unreliable.