Method-dependent differences in VO₂ peak determination and their implications for percentage-based exercise prescription in elite rowers.

purposePrecise determination of peak oxygen uptake (VO₂peak) is important for athlete profiling and exercise prescription. However, common data-processing approaches applied to breath-by-breath gas-exchange data may yield different VO₂peak values, particularly in elite athletes with high ventilatory rates. This study compared three commonly used VO₂peak determination methods and quantified their impact on percentage-based exercise prescription in national-level rowers.

methodsTwenty-six national-level male rowers performed a discontinuous incremental rowing test to volitional exhaustion on a wind-resistance ergometer. Breath-by-breath VO₂ data obtained during the final stage were processed using three approaches: (1) Raw Peak, defined as the highest single-breath value; (2) 30-s moving average, used as the pre-specified reference processing approach; and (3) Auto, defined as the device-reported VO₂peak value from the metabolic cart software using default settings. Repeated-measures ANOVA, pairwise comparisons, correlation and regression analyses, and Bland–Altman agreement analyses were performed. In addition, an illustrative simulation was conducted to examine the downstream consequences of method-dependent VO₂peak differences for percentage-based exercise prescription.

resultsA significant main effect of processing method was observed (p < 0.001). Raw Peak (6.10 ± 0.40 L·min⁻¹) was significantly higher than the 30-s moving average (5.50 ± 0.40 L·min⁻¹), representing a mean overestimation of 10.9% (Cohen’s d = 2.52). Auto (5.39 ± 0.36 L·min⁻¹) was significantly lower than the reference method by 1.9% (Cohen’s d = -0.73). The protocol elicited high physiological strain, with blood lactate reaching 11.46 ± 1.95 mmol·L⁻¹ at 3 min post-exercise. Although correlations between methods were strong (r ≈ 0.80–0.93), Bland–Altman analysis showed substantial systematic disagreement, including a mean bias of + 599 mL·min⁻¹ for Raw Peak versus the 30-s moving average. When a fixed workload corresponding to 80% of the reference VO₂peak was normalized to the other methods, its apparent relative intensity differed by 9.4% points between Raw Peak and Auto.

conclusionCommon VO₂peak processing methods applied to the same breath-by-breath dataset are strongly associated but not interchangeable in elite rowers. Raw single-breath values substantially inflate VO₂peak relative to time-averaged estimates, and these discrepancies propagate into meaningful bias when exercise intensity is prescribed as a percentage of VO₂peak. Standardizing VO₂peak processing procedures is therefore important for valid monitoring and consistent percentage-based exercise prescription, especially when practitioners interpret relatively small longitudinal changes in high-performance settings.