A comparison of two methods for the calculation of accumulated oxygen deficit

The aim of this study was to compare accumulated oxygen deficit data derived using two different exercise protocols with the aim of producing a less time-consuming test specifically for use with athletes. Six road and four track male endurance cyclists performed two series of cycle ergometer tests. The first series involved five 10 min sub-maximal cycle exercise bouts, a VO2peak test and a 115% VO2peak test. Data from these tests were used to estimate the accumulated oxygen deficit according to the calculations of Medbø et al. (1988). In the second series of tests, participants performed a 15 min incremental cycle ergometer test followed, 2 min later, by a 2 min variable resistance test in which they completed as much work as possible while pedalling at a constant rate. Analysis revealed that the accumulated oxygen deficit calculated from the first series of tests was higher (P < 0.02) than that calculated from the second series: 52.3 +/- 11.7 and 43.9 +/- 6.4 ml x kg(-1), respectively (mean +/- s). Other significant differences between the two protocols were observed for VO2peak, total work and maximal heart rate; all were higher during the modified protocol (P < 0.01 and P < 0.02, respectively). Oxygen kinetics were also significantly faster during the modified 2 min maximal test. We conclude that the difference in accumulated oxygen deficit between protocols was probably due to a reduced oxygen uptake, possibly caused by a slower oxygen on-response during the 115% VO2peak test in the first series, and VO2-power output regression differences caused by an elevated VO2 during the early stages of the second series.