Murai Fumiko, So Rina, Matsuo Tomoaki
Research Center for Overwork-Related Disorders, National Institute of Occupational Safety and Health, Japan, Kawasaki, Japan.
Ergonomics Research Group, National Institute of Occupational Safety and Health, Japan, Kawasaki, Japan.
Eur J Appl Physiol. 2025 May 8. doi: 10.1007/s00421-025-05786-2.
Conventional assessment of cardiorespiratory fitness (CRF) requires specialized equipment and designated spaces, limiting accessibility. To address this, the modified National Institute of Occupational Safety and Health, Japan step test (mJST) was developed for self-assessment without a step board. This study evaluated the reliability and validity of the mJST.
A total of 131 participants (49% female, aged 30-59) were divided into a derivation group (n = 82) to establish an estimated maximal oxygen consumption ( O) model using multiple regression, and validation group (n = 49) to test the accuracy of the model. All participants completed the mJST and a O treadmill test. The mJST comprised whole-body exercise for 3min and 40s followed by a 2-min recovery period. Heart rates (HRs) during the mJST were self-recorded using a wrist-worn device and measured via electrocardiograph. Test-retest reliability and validity were assessed using intraclass correlation coefficients (ICCs) and Bland-Altman analysis.
Excellent test-retest reliability was observed with electrocardiograph HRs (ICC = 0.92); however, fair to good reliability was observed with the wrist-worn device (ICC = 0.75). Bland-Altman analysis showed that mJST overestimated O by 1.24 mL·kg·min, likely owing to discrepancies in HR readings from the wrist-worn device. The correlation between estimated and measured O was moderate (r = 0.68).
Eliminating the step board in step tests may aid in regular assessments of CRF to support ongoing health management. Despite limitations in device accuracy, the mJST demonstrated sufficient reliability and validity as a practical tool.
传统的心肺适能（CRF）评估需要专门的设备和指定的空间，限制了其可及性。为解决这一问题，日本国家职业安全与健康研究所改良台阶试验（mJST）被开发用于无需台阶板的自我评估。本研究评估了mJST的信度和效度。
总共131名参与者（49%为女性，年龄30 - 59岁）被分为推导组（n = 82），使用多元回归建立估计最大摄氧量（ O）模型，以及验证组（n = 49），以测试该模型的准确性。所有参与者均完成mJST和 O跑步机测试。mJST包括3分钟40秒的全身运动，随后是2分钟的恢复期。mJST期间的心率（HRs）使用腕戴设备自行记录，并通过心电图测量。使用组内相关系数（ICCs）和布兰德-奥特曼分析评估重测信度和效度。
心电图测量的HRs显示出极好的重测信度（ICC = 0.92）；然而，腕戴设备的信度为中等至良好（ICC = 0.75）。布兰德-奥特曼分析表明，mJST高估 O 1.24 mL·kg·min，这可能是由于腕戴设备的HR读数存在差异。估计的和测量的 O之间的相关性为中等（r = 0.68）。
在台阶试验中去除台阶板可能有助于定期评估CRF，以支持持续的健康管理。尽管设备准确性存在局限性，但mJST作为一种实用工具显示出足够的信度和效度。
