The changes of lifestyle in modern society bring great threat to human health. Enhancing the level of physical activity(PA), which usually accounts for 20% of the total energy expenditure, can effectively decrease and control the occurrence of chronic non-infectious diseases and reduce the burden of social medical service. Portable telemetric gas metabolic systems can assess PA in free state. It has been applied to health promotion researches, the development and application of smart phones, wearable devices and visual reality equipment as well as competitive sports researches. However, people do not understand much about the correct use of the systems. The paper focuses on the reliability and validity of several portable telemetric gas metabolic systems, including Cosmed K4b2, Metamax 3B/VmaxST, Oxycon Mobile and VO2000, at different environments and conditions, especially the core indexes of VO2, VCO2 and VE, so as to provide reference for the relative research and application. |