Assessment Of Light Activities In Adults Using A Pattern-recognition Activity Monitor

Abstract

Non-exercise activity thermogenesis (NEAT) is the most variable component of energy expenditure (EE) in humans. The importance of NEAT in human energy balance supports the need for accurate and objective tools to measure light activity EE under free-living conditions. The Sensewear Pro armband (SWA) monitor integrates data from multiple sensors (including heat related sensors) and has potential for assessing the energy cost of light intensity, non-locomotor activities typically labeled as NEAT. PURPOSE: The purpose of the study was to evaluate the accuracy of the SWA monitor for assessing light (fidgeting) activities. METHODS: Fifteen males and 15 females (mean ages: 36.3±9.7 and 40.1±11.5, respectively) completed a resting metabolic rest assessment (RMR) and 4 light intensity activities (sitting, sitting/fidgeting, standing and standing/fidgeting) for intervals of 7 minutes each. Participants wore the SWA monitor and a portable metabolic analyzer (Oxycon Mobile, OM) during the activities. Data from the SWA monitor and the OM were processed on a minute-by-minute basis and merged by time. Percent increase over resting EE was computed for the SWA and OM. T-tests were computed to evaluate the accuracy of group level estimates of EE from the SWA. RESULTS: The percent increases in EE for the 4 activities were as follows: sitting (23.9%), sitting/fidgeting (33.4%), standing (18.2%) and standing/fidgeting (51.3%). The corresponding increases in estimated EE by the SWA were as follows: sitting (6.3%), sitting/fidgeting (39.3%) standing (3.4%) and standing/fidgeting (69.9%). Differences in EE estimation were non-significant for sitting/fidgeting (p=0.49) and standing/fidgeting (p=0.09), and were significant for sitting (p=0.006) and standing (p=0.03). CONCLUSION: The results demonstrate that the SWA is able to detect subtle changes in EE during light lifestyle activities. Because participants did not engage in locomotor activities during the protocol, it is likely that the heat flux variables detected the increased EE associated with the fidgeting activities. Additional work is needed to better understand the potential of the SWA for assessing light activities and NEAT.