Assessment of physical activity and energy expenditure by GPS combined with accelerometry in real-life conditions
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Published on: June 20, 2025
Dac Minh Tuan Nguyen1, Virgile Lecoultre, Yoshiyuki Sunami
1Dept of Cell Biology and Morphology, Lausanne University, Lausanne, Switzerland.
Background:
Physical activity (PA) and related energy expenditure (EE) is often assessed by means of a single technique. Because of inherent limitations, single techniques may not allow for an accurate assessment both PA and related EE. The aim of this study was to develop a model to accurately assess common PA types and durations and thus EE in free-living conditions, combining data from global positioning system (GPS) and 2 accelerometers.
Methods:
Forty-one volunteers participated in the study. First, a model was developed and adjusted to measured EE with a first group of subjects (Protocol I, n = 12) who performed 6 structured and supervised PA. Then, the model was validated over 2 experimental phases with 2 groups (n = 12 and n = 17) performing scheduled (Protocol I) and spontaneous common activities in real-life condition (Protocol II). Predicted EE was compared with actual EE as measured by portable indirect calorimetry.
Results:
In protocol I, performed PA types could be recognized with little error. The duration of each PA type could be predicted with an accuracy below 1 minute. Measured and predicted EE were strongly associated (r = .97, P < .001).
Conclusion:
Combining GPS and 2 accelerometers allows for an accurate assessment of PA and EE in free-living situations.
