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

Vähä‐Ypyä, Henri; Vasankari, Tommi; Husu, Pauliina; Mänttäri, Ari; Vuorimaa, Timo; Suni, Jaana; Sievänen, Harri

doi:10.1371/journal.pone.0134813

Cited by 184 publications

(223 citation statements)

References 31 publications

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“…The data was analyzed with novel, universal and valid algorithms [30, 32] and the study sample included both men and women within a wide age range. Although the accelerometer used in the present study is not widely used, the analysis methods are universal and can be used with any tri-axial accelerometer collecting data in raw mode [30].…”

Section: Discussionmentioning

confidence: 99%

Objectively measured sedentary behavior and physical activity in a sample of Finnish adults: a cross-sectional study

et al. 2016

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BackgroundRegular physical activity (PA) confers many positive effects on health and well-being. Sedentary behavior (SB), in turn, is a risk factor for health, regardless of the level of moderate to vigorous PA. The present study describes the levels of objectively measured SB, breaks in SB, standing still and PA among Finnish adults.MethodsThis cross-sectional analysis is based on the sub-sample of the population-based Health 2011 Study of Finnish adults. The study population consisted of 18-to-85-year old men and women who wore a waist-worn triaxial accelerometer (Hookie AM 20) for at least 4 days, for at least 10 h per day (n = 1587) during a week. PA and SB were objectively assessed from the raw accelerometric data using novel processing and analysis algorithms with mean amplitude deviation as the processing method. The data was statistically analyzed using cross-tabulations, analysis of variance and analysis of covariance.ResultsThe participants were on average 52 years old, 57 % being women. Participants were sedentary 59 % of their waking wear time, mainly sitting. They spent 17 % of the time standing still, 15 % in light intensity PA, 9 % in moderate PA and less than 1 % in vigorous PA. Participants aged 30–39 years had the highest number of breaks in SB per day. Younger participants (<30 years of age) had more moderate and vigorous PA than older ones (≥60 years of age), and 30–60-year-olds had the greatest amount of light PA.ConclusionsParticipants spent nearly 60 % of their waking time sedentary, and the majority of their daily PA was light. From a public health perspective it is important to find effective ways to decrease SB as well as to increase the level of PA. Our analysis method of raw accelerometer data may allow more precise assessment of dose-response relationships between objectively measured PA and SB and various indicators of health and well-being.

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Section: Discussionmentioning

confidence: 99%

Objectively measured sedentary behavior and physical activity in a sample of Finnish adults: a cross-sectional study

et al. 2016

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“…A strong correlation ( R 2 = 0.94) has been found between incident MAD measured with a waist-worn device (Hookie AM20, Traxmeet, Finland) and oxygen consumption in walking and running (Vähä-Ypyä et al, 2015a). For the epoch of interest, the MAD is calculated from the resultant of the three orthogonal accelerations and it describes the mean variation of the dynamic acceleration component around the static component.…”

Section: Introductionmentioning

confidence: 99%

“…Mean amplitude deviation (MAD) is a recently proposed universal method to analyse raw triaxial acceleration signals (Aittasalo et al, 2015; Vähä-Ypyä et al, 2015a,b). A strong correlation ( R 2 = 0.94) has been found between incident MAD measured with a waist-worn device (Hookie AM20, Traxmeet, Finland) and oxygen consumption in walking and running (Vähä-Ypyä et al, 2015a).…”

Section: Introductionmentioning

confidence: 99%

Measuring Physical Activity in Free-Living Conditions—Comparison of Three Accelerometry-Based Methods

et al. 2017

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We examined the agreement in time spent on different physical activity (PA) levels using (1) mean amplitude deviation (MAD) of raw acceleration from the hip, (2) wrist-worn Polar Active, and (3) hip-worn Actigraph counts using Freedson's cut-points among adults under free-living conditions. PA was measured in 41 volunteers (mean age 47.6 years) for 14 days. Two MET-based threshold sets were used for MAD and Polar Active for sedentary time (ST) and time spent in light (LPA), moderate (MPA), and vigorous (VPA) PA. Actigraph counts were divided into PA classes, ≤100 counts/min for ST and Freedson's cut-points for LPA, MPA, and VPA. Analysis criteria were simultaneous use of devices for at least 4 days of >500 min/d. The between-method differences were analyzed using a repeated measures analysis of variance test. Bland-Altman plots and ROC graphs were also employed. Valid data were available from 27 participants. Polar Active produced the highest amount of VPA with both thresholds (≥5 and ≥6 MET; mean difference 17.9–30.9 min/d, P < 0.001). With the threshold 3–6 MET for MPA, Polar Active indicated 19.2 min/d more than MAD (95% CI 5.8–32.6) and 51.0 min/d more than Actigraph (95% CI 36.7–65.2). The results did not differ with 3.5–5 MET for MPA [F(1.44, 37.43) = 1.92, P = 0.170]. MAD and Actigraph were closest to each other for ST with the threshold < 1.5 MET (mean difference 22.2 min/d, 95% CI 7.1–37.3). With the threshold <2 MET, Polar Active and Actigraph provided similar results (mean difference 7.0 min/d, 95% CI −17.8–31.7). Moderate to high agreement (area under the ROC curve 0.806–0.963) was found between the methods for the fulfillment of the recommendation for daily moderate-to-vigorous PA of 60 min. In free-living conditions the agreement between MAD, Polar Active, and Actigraph for measuring time spent on different activity levels in adults was dependent on the activity thresholds used and PA intensity. ROC analyses showed moderate to high agreement for the fulfillment of the recommendation for daily MVPA. Without additional statistical adjustment, these methods cannot be used interchangeably when measuring daily PA, but any of the methods can be used to identify persons with insufficient daily amount of MVPA.

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“…Minimum requirement for the inclusion of accelerometer data for further analyses was 4 days with at least 10 h of wearing time each day. The accelerometer data was analyzed for metabolic equivalent (MET) intensities and step counts by using a mean amplitude deviation according to the previously published validation [15]. Saliva samples with concurrent ratings of perceived exertion (RPE) [16] were collected 6 times during one typical working day by using cotton swabs according to the manufacturer's guidelines (Salivette, Sarstedt, Nümbrecht, Germany).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of occupational physical load during 6-month international crisis management operation

Pihlainen

Santtila

Vasankari

et al. 2017

Int J Occup Med Environ Health

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Objectives: Generally, operational military duties are associated with a variety of stressors, such as prolonged physical activity (PA). However, limited information is available on the occupational workload or changes in PA during international military operations. Thus, the aim of the study was to investigate the changes in body composition, stress biomarkers, PA, and heart rate (HR) responses of 79 male soldiers during a 6-month international crisis management operation. Material and Methods: Measurements were conducted 3 times in South-Lebanon during the operation. Body composition was assessed by the bioelectrical impedance method. Blood samples were analyzed for serum testosterone, sex-hormone binding globulin (SHBG), cortisol and insulin-like growth factor. Saliva sampling was used for analyzing stress biomarkers, cortisol and α-amylase. Heart rate and physical activity were monitored by a recordable belt and tri-axial accelerometer, respectively. Results: Increases in muscle mass (39.2±4.1 vs. 39.5±4.2 kg, p < 0.05) and testosterone (15.9±4.6 vs. 17.2±4 nmol/l, p < 0.01), and reductions in PA variables (e.g., daily step count 9472±2547 vs. 8321±2720, p < 0.05) were observed during the first half (i.e., PRE-MID) of the study. The increase in muscle mass remained significant during the latter half (PRE-POST, 39.2±4.1 vs. 39.6±4.4 kg, p < 0.05), but also fat mass increased (MID-POST, 10.6±4.6 vs. 11.0±4.7 kg, p < 0.05) while SHBG (MID-POST, 31.8±12.1 vs. 26.6±13.2 nmol/l, p < 0.01) and cortisol (MID-POST, 445±116 vs. 400±123 nmol/l, p < 0.05) decreased. With the exception of increased concentration of salivary α-amylase (PRE-POST, 36.5±33.7 vs. 55.1±39.7 U/ml), the acute stress biomarkers and HR responses remained unchanged. Furthermore, the low quantity of PA, low HR values and subjective ratings of exertion refer to rather light physical workload. Conclusions: Due to the operatively calm nature of the working environment, the present soldiers did not express any significant signs of physical overload during the study period. Int J Occup Med Environ Health 2018;31(2): 185 -197

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

Cited by 184 publications

References 31 publications

Objectively measured sedentary behavior and physical activity in a sample of Finnish adults: a cross-sectional study

Objectively measured sedentary behavior and physical activity in a sample of Finnish adults: a cross-sectional study

Measuring Physical Activity in Free-Living Conditions—Comparison of Three Accelerometry-Based Methods

Evaluation of occupational physical load during 6-month international crisis management operation

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