Carrying loads: Validating a portable tri-axial accelerometer during frequent and brief physical activity.
OBJECTIVE
The aim of this study is to evaluate the validity of the SenseWear Armband™ (SWA, Model MF-SW, BodyMedia Inc.) as a tool to assess daily brief, light- to moderate-intensity activities.


METHODS
A total of 41 volunteers were recruited (27 males, 14 females) to perform several trials, including a resting metabolic rate test and a number of walking trials while carrying different loads in a backpack.


METHODS
Energy expenditure during trials was measured using both the SWA™ mini device, with the indirect calorimetry method (MasterScreen CPX and Oxycon Mobile JAEGER™ devices) used for validated comparative measurement.


RESULTS
The SWA™ mini shows agreement with indirect calorimetry in all trials. However, the SWA™ mini over-estimated expenditure in all participants. Individual assessment estimates with the SWA™ mini also exhibited random errors. The variations in energy expenditure (EE) resulting from increased carried loads during the trials were not statistically significant when EE was measured with the SWA™ mini. Furthermore, Metabolic Equivalent of Task (MET) calculation, highly dependent on estimated energy expenditure per unit time, also was likely overestimated. In contrast, the SWA™ mini provided estimates of the resting metabolic rate with a small error.


CONCLUSIONS
The SWA™ mini is not a valid device for estimating energy expenditure in brief light- or moderate activities.
Escuela Interuniversitaria de Posgrado en Evolución Humana, Universidad de Burgos, Spain. Electronic address: guillermozorre@gmail.com.
G
G
Zorrilla-Revilla
National Research Centre on Human Evolution (CENIEH), Spain. Electronic address: ana.mateos@cenieh.es.
A
A
Mateos
National Research Centre on Human Evolution (CENIEH), Spain. Electronic address: olalla.prado@cenieh.es.
O
O
Prado-Nóvoa
National Research Centre on Human Evolution (CENIEH), Spain. Electronic address: marco.vidal@cenieh.es.
M
M
Vidal-Cordasco
National Research Centre on Human Evolution (CENIEH), Spain. Electronic address: jesus.rodriguez@cenieh.es.
J
J
Rodríguez
D061725:Accelerometry / Q000295:instrumentation* / Q000379:methods; D000328:Adult; D001481:Basal Metabolism / Q000502:physiology; D002151:Calorimetry / Q000379:methods; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D016138:Walking / Q000502:physiology*; D000076251:Wearable Electronic Devices; D016474:Weight-Bearing / Q000502:physiology*; D055815:Young Adult
Accelerometry; Energy expenditure; Indirect calorimetry; Physical activity; Resting metabolic rate; SenseWear Armband™ mini