A Comparison of Energy Expenditure Estimates From SenseWear Activity Monitor Armbands During Exercise

Abstract

The SenseWear Pro Armband (SWA) (BodyMedia, Inc.) is a commercially available portable objective device that provides an estimate of energy expenditure (EE). The SWA has shown acceptable validity and reliability in previous studies examining various exercise modes and intensities. The SenseWear Mini Armband (MINI) is the next generation of this technology that has allowed for a downsizing of the SWA. However, the EE estimated by the MINI and SWA during various modes of exercise has not been examined. PURPOSE: To compare the EE estimated by the SWA to the MINI during various modes of exercise. METHODS: Thirty subjects (age: 25.2±4.9 yrs; BMI: 24.4±2.9 kg/m2) were randomized to three of five exercising conditions (walking, n=18; elliptical trainer, n=19; stepping on an adaptive motion trainer, n=18; stationary cycling, n=20; outdoor cycling, n=15). Each exercise session was 20 minutes and performed on separate days. For each exercise session the subject wore the MINI on the left arm and the SWA on the right arm. EE was estimated using proprietary algorithms developed by the manufacturer (software version 7.0) and indirect calorimetry served as the criterion measure. RESULTS: EE estimated by the MINI was significantly higher than the SWA by 19.4±9.7 kcal during walking, 22.7±13.5 kcal during stepping, and 11.8±8.0 kcal during elliptical exercise (p=0.001). There was a non-significant difference between MINI and SWA in EE of 9.1±19.9 kcal during stationary cycling and 2.5±15.8 kcal during outdoor cycling. Indirect calorimetry was significantly associated with EE during walking (r=0.91; r=0.90), stepping (r=.75; r=.84), elliptical exercise (r=0.65; r=0.73) and outdoor cycling (r=0.59; r=0.59) for the MINI and SWA, respectively (p<0.05). EE during stationary cycling was significantly associated with indirect calorimetry for the MINI (r=.48, p=0.03), but not for the SWA. CONCLUSIONS: These results suggest that while the MINI provides EE estimates that are greater than the SWA for selected exercises, these data are significantly correlated with measured EE from indirect calorimetry. This next generation of this technology may be a viable alternative to the SWA for estimating EE. However, additional research is needed to confirm these findings and to potentially refine the proprietary algorithms used to estimate EE.