Dolezal B A, Barr D, Boland D M, Smith D L, Cooper C B
Department of Medicine and Physiology, Exercise Physiology Research Laboratory, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA,
Department of Health and Exercise Sciences, First Responder Health and Safety Laboratory, Skidmore College, Saratoga Springs, NY 12866, USA.
Occup Med (Lond). 2015 Mar;65(2):143-6. doi: 10.1093/occmed/kqu189. Epub 2015 Jan 7.
The Wellness-Fitness Initiative submaximal treadmill exercise test (WFI-TM) is recommended by the US National Fire Protection Agency to assess aerobic capacity (VO2 max) in firefighters. However, predicting VO2 max from submaximal tests can result in errors leading to erroneous conclusions about fitness.
To investigate the level of agreement between VO2 max predicted from the WFI-TM against its direct measurement using exhaled gas analysis.
The WFI-TM was performed to volitional fatigue. Differences between estimated VO2 max (derived from the WFI-TM equation) and direct measurement (exhaled gas analysis) were compared by paired t-test and agreement was determined using Pearson Product-Moment correlation and Bland-Altman analysis. Statistical significance was set at P < 0.05.
Fifty-nine men performed the WFI-TM. Mean (standard deviation) values for estimated and measured VO2 max were 44.6 (3.4) and 43.6 (7.9) ml/kg/min, respectively (P < 0.01). The mean bias by which WFI-TM overestimated VO2 max was 0.9ml/kg/min with a 95% prediction interval of ±13.1. Prediction errors for 22% of subjects were within ±5%; 36% had errors greater than or equal to ±15% and 7% had greater than ±30% errors. The correlation between predicted and measured VO2 max was r = 0.55 (standard error of the estimate = 2.8ml/kg/min).
WFI-TM predicts VO2 max with 11% error. There is a tendency to overestimate aerobic capacity in less fit individuals and to underestimate it in more fit individuals leading to a clustering of values around 42ml/kg/min, a criterion used by some fire departments to assess fitness for duty.
美国国家消防协会推荐采用健康与健身倡议亚极量跑步机运动测试（WFI-TM）来评估消防员的有氧能力（最大摄氧量，VO₂ max）。然而，通过亚极量测试预测VO₂ max可能会产生误差，从而导致关于体能的错误结论。
研究通过WFI-TM预测的VO₂ max与其通过呼出气体分析直接测量值之间的一致性水平。
进行WFI-TM直至自愿疲劳。通过配对t检验比较估计的VO₂ max（由WFI-TM方程得出）与直接测量值（呼出气体分析）之间的差异，并使用Pearson积矩相关和Bland-Altman分析确定一致性。设定P < 0.05为统计学显著性水平。
59名男性进行了WFI-TM。估计和测量的VO₂ max的平均值（标准差）分别为44.6（3.4）和43.6（7.9）ml/kg/min（P < 0.01）。WFI-TM高估VO₂ max的平均偏差为0.9ml/kg/min，95%预测区间为±13.1。22%受试者的预测误差在±5%以内；36%的误差大于或等于±15%，7%的误差大于±30%。预测的和测量的VO₂ max之间的相关性为r = 0.55（估计标准误差 = 2.8ml/kg/min）。
WFI-TM预测VO₂ max的误差为11%。对于体能较差的个体有高估有氧能力的趋势，而对于体能较好的个体则有低估的趋势，导致数值聚集在42ml/kg/min左右，这是一些消防部门用于评估执勤体能的标准。
