Research Institute for Sport and Exercise Science (UCRISE), University of Canberra, Bruce, Canberra, ACT, Australia.
Eur J Appl Physiol. 2024 Jul;124(7):2153-2160. doi: 10.1007/s00421-024-05447-w. Epub 2024 Mar 2.
Accurately measuring sweat sodium concentration ([Na]) in the field is advantageous for coaches, scientists, and dieticians looking to tailor hydration strategies. The MX3 hydration testing system is a new portable analyser that uses pre-calibrated biosensors to measure sweat [Na]. This study aimed to assess the validity and reliability of the MX3 hydration testing system.
Thirty-one (11 females) recreationally active participants completed one experimental trial. During this trial, participants exercised at a self-selected pace for 45 min in a warm environment (31.5 ± 0.8 °C, 63.2 ± 1.3% relative humidity). Sweat samples were collected from three measurement sites using absorbent patches. The samples were then analysed for sweat [Na] using both the MX3 hydration testing system and the Horiba LAQUAtwin-NA-11. The reliability of the MX3 hydration testing system was determined following two measurements of the same sweat sample.
The mean difference between measurements was 0.1 mmoL·L (95% limits of agreement (LoA): - 9.2, 9.4). The analyser demonstrated a coefficient of variation (CV) of 5.6% and the standard error of measurement was 3.3 mmoL·L. When compared to the Horiba LAQUAtwin-NA-11, there was a mean difference of - 1.7 mmoL·L (95% LoA: - 0.25 , 0.25 ) and the CV was 9.8%.
The MX3 hydration testing system demonstrated very good single-trial reliability, moderate agreement and a very good CV relative to the Horiba LAQUAtwin-Na-11. To further validate its performance, the MX3 hydration testing system should be compared with analytical techniques known for superior reliability and validity.
在现场准确测量汗钠浓度([Na])，有利于教练、科学家和营养师制定个性化的水合策略。MX3 水合测试系统是一种新的便携式分析仪，它使用经过预校准的生物传感器来测量汗[Na]。本研究旨在评估 MX3 水合测试系统的有效性和可靠性。
31 名（11 名女性）有运动习惯的参与者完成了一项实验性试验。在这项试验中，参与者在温暖的环境中（31.5±0.8°C，63.2±1.3%相对湿度）以自定速度运动 45 分钟。使用吸收垫从三个测量部位采集汗液样本。然后使用 MX3 水合测试系统和 Horiba LAQUAtwin-NA-11 对样本进行汗[Na]分析。通过对同一汗液样本进行两次测量，确定了 MX3 水合测试系统的可靠性。
两次测量之间的平均差值为 0.1 mmoL·L（95% 置信区间（LoA）：-9.2，9.4）。该分析仪的变异系数（CV）为 5.6%，测量标准差为 3.3 mmol·L。与 Horiba LAQUAtwin-NA-11 相比，差值平均为-1.7 mmoL·L（95% LoA：-0.25，0.25），CV 为 9.8%。
与 Horiba LAQUAtwin-NA-11 相比，MX3 水合测试系统在单次试验中表现出非常好的可靠性、适度的一致性和非常好的 CV。为了进一步验证其性能，应将 MX3 水合测试系统与以可靠性和有效性著称的分析技术进行比较。
