Heart Rate Index Corrects for The Limitations of Heart Rate Assessment of Occupational Physical Activity

HR (heart rate) is the simplest physiological variable to measure for estimation of exercise intensity (EI) and energy expenditure (EE). The recent rapid development of wearable technology incorporating HR and motion sensors facilitates measurement of EE over extended periods of time and this information may assist individuals in making healthy lifestyle changes. In both a home and work setting, technology has resulted in decreased levels of physical activity. Within manufacturing industries, automation, mechanisation and robotics have reduced the physical demands of OPA resulting in increased sedentary behaviour [1] considered to be associated with an adverse health risk [2]. The use of HR to estimate EI is reliant on the linear relationship of HR to oxygen uptake (VO2) [3]. However cardiorespiratory fitness (CRF) and tobacco smoking will influence this relationship [3] and to use HR without individual calibration of the HR-VO2 limits its use. When using HR to estimate EE at near sedentary levels of activity where the HR-VO2 relationship is less precise, the flex HR (HRflex) method is frequently used [4]. Individual HR-VO2 calibration is a prerequisite and in defining HRflex as the average of the highest resting HR (HRrest) and the lowest level of activity HR (HRactivity), time spent below HRflex is considered to be 1 MET (1 MET being the VO2 at rest, namely 3.5mL O2·kg-1·min-1)[5]. The ability to correct for variables such as CRF and smokResearch Article Exercise Medicine Open Access eISSN: 2508-9056