The validity of predicting maximal oxygen uptake from perceptually regulated graded exercise tests of different durations.

The purpose of this study was to assess the validity of predicting maximal oxygen uptake [V(.-)((O)(2)(max))] from sub-maximal V(.-)((O)(2)) values elicited during perceptually regulated exercise tests of 2- and 4-min duration. Nineteen physically active men and women (age range 19-23 years) volunteered to participate in two graded exercise tests to volitional exhaustion to measure V(.-)((O)(2)(max)) [V(.-)((O)(2)(max))(GXT)], at the beginning and end of a 2-week period, and four incremental, perceptually regulated tests to predict [V(.-)((O)(2)(max))] in the intervening period. Effort production tests comprised 2 x 2-min and 2 x 4-min bouts on a cycle ergometer, perceptually regulated at intensities of 9, 11, 13, 15 and 17 on the Borg 6-20 rating of perceived (RPE) scale, in that order. Individual linear relationships between RPE and V(.-)((O)(2) for RPE ranges of 9-17, 11-17 and 9-15 were extrapolated to RPE 20 to predict [V(.-)((O)(2)(max))]. The prediction of [V(.-)((O)(2)(max))] was not moderated by gender. Although, [V(.-)((O)(2)(max))] estimated from RPE 9-17 of trial 1 of the 2-min protocol was significantly lower (P < 0.05) than [V(.-)((O)(2)(max))(GXT)], and V(.-)((O)(2)(max)) predicted from the 4-min trials, the V(.-)((O)(2)(max)) predicted from trial 2 of the 2-min protocol was a more accurate prediction of [V(.-)((O)(2)(max))(GXT)], across all trials. The intraclass correlation coefficient (R) was also higher between [V(.-)((O)(2)(max))(GXT)], and [V(.-)((O)(2)(max))] predicted from trial 2 of the 2-min protocol compared to both trials in the 4-min protocol (R = 0.95, 0.88 and 0.79, respectively). Similar results were observed for RPE ranges 9-15 and 11-17. Results suggest that a sub-maximal, perceptually guided, graded exercise protocol, particularly of a 2-min duration, provides acceptable estimates of maximal aerobic power, which are not moderated by gender.