Department of Exercise Science, Syracuse University, 820 Comstock Ave, Syracuse, NY, 13210, USA.
Eur J Appl Physiol. 2021 Jan;121(1):209-217. doi: 10.1007/s00421-020-04514-2. Epub 2020 Oct 4.
Portable methods for assessing energy expenditure outside the laboratory and clinical environments are becoming more widely used. As such, it is important to understand the accuracy of such devices. Therefore, the purpose was to determine the reliability and validity of the COSMED K5 portable metabolic system.
Reliability and validity were assessed in 27 adults (age: 27 ± 5 years; n = 15 women) using a walking protocol. The protocol consisted of a 5-min walk/2-min rest cycle starting at 1.5 mph and increasing in 0.5-mph increments to 4.0 mph. During visit one, participants wore the K5 to assess oxygen consumption ([Formula: see text]O), carbon dioxide production ([Formula: see text]CO), and other metabolic variables. Two to seven days later, the protocol was repeated twice with the COSMED K5 and K4b systems in a randomized, counterbalanced order.
Intraclass correlation coefficients (ICC) revealed that the K5 reliably measured [Formula: see text]O (ICC 0.64-0.85) and [Formula: see text]CO across all walking speeds (ICC 0.50-0.80), with stronger reliability at faster walking speeds compared with slower speeds. Moderate-to-strong relationships were observed for measured gases between the K5 and K4b. Specifically, [Formula: see text]O exhibited a moderately high-to-high relationship between devices (r = 0.72-0.82), and a similarly moderately high-to-high relationship was observed for [Formula: see text]CO (r = 0.68-0.82). While there were no differences in [Formula: see text]O measured between devices (p ≥ 0.10), the K5 provided lower [Formula: see text]CO readings than the K4b during the 3.0, 3.5, and 4.0 mph walking speeds (p ≤ 0.02).
The K5 provided reliable and valid measures of metabolic variables, with greater reliability and validity at faster walking speeds.
便携式方法来评估实验室和临床环境以外的能量消耗正变得越来越广泛。因此，了解这些设备的准确性是很重要的。因此，目的是确定 COSMED K5 便携式代谢系统的可靠性和有效性。
在 27 名成年人（年龄：27±5 岁；n=15 名女性）中使用步行方案评估可靠性和有效性。方案包括 5 分钟步行/2 分钟休息循环，起始速度为 1.5 英里/小时，并以 0.5 英里/小时的增量增加至 4.0 英里/小时。在第一次访问中，参与者佩戴 K5 以评估耗氧量（[Formula: see text]O）、二氧化碳产生量（[Formula: see text]CO）和其他代谢变量。两天到七天后，以随机、平衡的顺序两次重复该方案，同时使用 COSMED K5 和 K4b 系统。
组内相关系数（ICC）显示，K5 在所有步行速度下可靠地测量[Formula: see text]O（ICC 0.64-0.85）和[Formula: see text]CO（ICC 0.50-0.80），在较快的步行速度下比在较慢的速度下具有更强的可靠性。在 K5 和 K4b 之间观察到测量气体之间存在中度到强的关系。具体来说，[Formula: see text]O 在设备之间表现出中等至高的关系（r=0.72-0.82），而[Formula: see text]CO 也表现出类似的中等至高的关系（r=0.68-0.82）。虽然设备之间的[Formula: see text]O 测量没有差异（p≥0.10），但在 3.0、3.5 和 4.0 英里/小时的步行速度下，K5 提供的[Formula: see text]CO 读数低于 K4b（p≤0.02）。
K5 提供了代谢变量可靠且有效的测量值，在较快的步行速度下具有更高的可靠性和有效性。
