Changing the number of submaximal exercise bouts effects calculation of MAOD

The aim of this present study was to evaluate the effect of the number of submaximal exercise bouts used to construct the power-VO2 regression, on calculations of MAOD through the sequential and systematic removal of the highest and lowest submaximal VO2 values from the standard ten point regression line. Eight trained male cyclists participated in this study. The mean (+/- SD) age, height, weight and VO2max for the subjects were 25+/-7 yr, 178.2+/-3.0 cm, 69.9+/-4.9 kg and 57.5+/-6.9 ml x kg(-1) x min(-1). After VO2max testing each subject undertook ten submaximal exercise bouts at between 30% and 90% VO2max and one supramaximal bout calculated to elicit 100% VO2max. Expired gases were measured via open circuit spirometry. The mean power output of the supramaximal bout was 336.5+/-442.5 W and the mean duration was 269.4+/-42.9 s. The correlation coefficients ranged from 0.981 to 0.996 while the MAOD values ranged from 29.6+/-15.7 ml O2 eq x kg(-1) to 61.3+/-44.7 ml O2 eq x kg(-1). When compared to the standard ten points, as a percentage difference, this difference ranged from 4.1+/-3.6% to 83.7+/-54.9%. The main finding of this study is that inaccuracies occur in the measurement of MAOD when less than ten points are used in the calculation. Further study is required for the development of a standardised protocol for the accurate, valid and reliable measurement of MAOD.