Validation of Cut-Points for Evaluating the Intensity of Physical Activity with Accelerometry-Based Mean Amplitude Deviation (MAD)

• DOI: 10.1371/journal.pone.0134813
• Publication Date: 2015-08-20T17:57:31Z
• Authors: Henri Vähä-Ypyä; Tommi Vasankari; Pauliina Husu; Ari Mänttäri; Timo Vuorimaa; Jaana Suni; Harri Sievänen
• Keywords: Intensity; Metabolic equivalent

Purpose Our recent study of three accelerometer brands in various ambulatory activities showed that the mean amplitude deviation (MAD) resultant acceleration signal performed best separating different intensity levels and provided excellent agreement between devices. The objective this was to derive a regression model estimates oxygen consumption (VO2) from MAD values validate MAD-based cut-points for light, moderate vigorous locomotion against VO2 within wide range speeds. Methods 29 participants pace-conducted non-stop test on 200 m long indoor track. initial speed 0.6 m/s it increased by 0.4 every 2.5 minutes until volitional exhaustion. could freely decide whether they preferred walk or run. During carried hip-mounted tri-axial mobile metabolic analyzer. calculated raw data compared directly measured incident VO2. Cut-point light activity set 3.0 equivalent (MET, 1 MET = 3.5 ml · kg-1 min-1) 6.0 as per standard use. Results very strong association. Within individuals, r 0.927 0.991 providing 0.969. optimal cut-point 91 mg (milligravity) 414 MET. Conclusion present is valid method terms slow walking fast running. Being device-independent trait, facilitates comparable, accurate results physical with all accelerometers data.