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Real-time estimation of daily physical activity intensity by a triaxial accelerometer and a gravity-removal classification algorithm

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Ohkawara, Kazunori, Oshima, Yoshitake, Hikihara, Yuki, Ishikawa-Takata, Kazuko, Tabata, Izumi, Tanaka, Shigeho·2011·British Journal of Nutrition

Abstract

We have recently developed a simple algorithm for the classification of household and locomotive activities using the ratio of unfiltered to filtered synthetic acceleration (gravity-removal physical activity classification algorithm, GRPACA) measured by a triaxial accelerometer. The purpose of the present study was to develop a new model for the immediate estimation of daily physical activity intensities using a triaxial accelerometer. A total of sixty-six subjects were randomly assigned into validation (n 44) and cross-validation (n 22) groups. All subjects performed fourteen activities while wearing a triaxial accelerometer in a controlled laboratory setting. During each activity, energy expenditure was measured by indirect calorimetry, and physical activity intensities were expressed as metabolic equivalents (MET). The validation group displayed strong relationships between measured MET and filtered synthetic accelerations for household (r 0·907, P < 0·001) and locomotive (r 0·961, P < 0·001) activities. In the cross-validation group, two GRPACA-based linear regression models provided highly accurate MET estimation for household and locomotive activities. Results were similar when equations were developed by non-linear regression or sex-specific linear or non-linear regressions. Sedentary activities were also accurately estimated by the specific linear regression classified from other activity counts. Therefore, the use of a triaxial accelerometer in combination with a GRPACA permits more accurate and immediate estimation of daily physical activity intensities, compared with previously reported cut-off classification models. This method may be useful for field investigations as well as for self-monitoring by general users.

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Metadata

Authors
Ohkawara, K., Oshima, Y., Hikihara, Y., Ishikawa-Takata, K., Tabata, I., & Tanaka, S.
Venue
British Journal of Nutrition
Published
2011-01-25
Volume
105
Issue
11
Pages
1681-1691
ISSN
  • 0007-1145 (ISSN-L)
  • 1475-2662
OpenAlex
W1964754398
Cited by
458
References
46
FWCI
5.01
Type
journal article
Language
en
Open access
bronze

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CoChat. (2026). Citation check: Real-time estimation of daily physical activity intensity by a triaxial accelerometer and a gravity-removal classification algorithm. https://app.cochat.ai/papers/10.1017/s0007114510005441
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Ohkawara, K., Oshima, Y., Hikihara, Y., Ishikawa-Takata, K., Tabata, I., & Tanaka, S. (2011). Real-time estimation of daily physical activity intensity by a triaxial accelerometer and a gravity-removal classification algorithm. British Journal of Nutrition. https://doi.org/10.1017/s0007114510005441

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