Mougin L, Bailey S J, Burnley M, Pearce R, Mears S A, Zanini M
School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.
Loughborough Sport, Loughborough University, Loughborough, UK.
Scand J Med Sci Sports. 2025 Aug;35(8):e70110. doi: 10.1111/sms.70110.
Step incremental exercise tests are widely used to assess endurance performance determinants; however, to what extent step duration influences oxygen uptake (V̇O) and carbon dioxide production (V̇CO) is unclear. This study assessed the influence of sampling duration on V̇O, V̇CO, and fat oxidation (Fat) across different exercise intensities and modalities, and participant age and biological sex during graded exercise tests. A total of 169 participants (41 females; peak V̇O [V̇Opeak]: 54.7 ± 8.6 mL/kg/min) completed a running (n = 96) or cycling (n = 73) submaximal step test with V̇O and V̇CO measured continuously. Each stage was 6 min, and three 30 s averaging windows (2.5-3, 3.5-4, and 4.5-5 min) were compared to the 5.5-6 min reference. Linear mixed models assessed the effects of averaging window, exercise intensity domain, biological sex, age, fitness status, and exercise modality. The analysis included 1031 valid stages (588 running; 443 cycling). In running, V̇O differences from the 6-min averaging window were observed at 3 (-28 mL/min), 4 (-15 mL/min), and 5-min averaging windows (-8 mL/min) (all p < 0.001), with similar results for V̇CO. No differences in V̇O or Fat between averaging windows were observed in cycling. These findings were consistent across exercise intensity, fitness status, biological sex, and age. Averaging window differences were < 2% for all conditions. Despite subtle differences, 3-, 4-, and 5-min averaging windows do not meaningfully impact V̇O, V̇CO, or Fat compared to a 6-min stage duration. In conclusion, stage durations of ≥ 3 min may be sufficient to estimate these variables in running and cycling in participants with a wide range of characteristics.
逐步递增运动测试被广泛用于评估耐力表现的决定因素；然而，步长时间对摄氧量（V̇O）和二氧化碳产生量（V̇CO）的影响程度尚不清楚。本研究评估了在分级运动测试中，采样持续时间对不同运动强度和方式、参与者年龄及生物性别的V̇O、V̇CO和脂肪氧化（Fat）的影响。共有169名参与者（41名女性；峰值V̇O [V̇Opeak]：54.7±8.6 mL/kg/min）完成了一项跑步（n = 96）或骑自行车（n = 73）的次最大步测试，并持续测量V̇O和V̇CO。每个阶段为6分钟，并将三个30秒的平均窗口（2.5 - 3、3.5 - 4和4.5 - 5分钟）与5.5 - 6分钟的参考窗口进行比较。线性混合模型评估了平均窗口、运动强度域、生物性别、年龄、健康状况和运动方式的影响。分析包括1031个有效阶段（588个跑步阶段；443个骑自行车阶段）。在跑步中，在3分钟（-28 mL/min）、4分钟（-15 mL/min）和5分钟平均窗口（-8 mL/min）观察到与6分钟平均窗口的V̇O差异（所有p < 0.001），V̇CO结果相似。在骑自行车时，未观察到平均窗口之间的V̇O或Fat差异。这些发现在运动强度、健康状况、生物性别和年龄方面是一致的。所有条件下平均窗口差异均<2%。尽管存在细微差异，但与6分钟的阶段持续时间相比，3分钟、4分钟和5分钟的平均窗口对V̇O、V̇CO或Fat没有显著影响。总之，≥3分钟的阶段持续时间可能足以估计具有广泛特征的参与者在跑步和骑自行车时的这些变量。
