Validity of the Pregnancy Physical Activity Questionnaire Short Form (PPAQ-SF).

To develop and evaluate the validity of the Pregnancy Physical Activity Questionnaire-Short Form (PPAQ-SF). A prospective cohort of participants (N=50) completed the updated PPAQ (long-form) and wore an ActiGraph for 7 days on the nondominant wrist in early, mid, and late pregnancy. The top ten questions with the highest relative contribution to the between-person variance in PPAQ-assessed total MET-hours/day were selected.

Cadence (steps/min) and relative intensity in 61 to 85-year-olds: the CADENCE-Adults study.

Background: We previously demonstrated that a heuristic (i.e., evidence-based, rounded yet practical) cadence threshold of ≥ 100 steps/min was associated with absolutely-defined moderate intensity physical activity (i.

Cadence (steps/min) as an indicator of the walk-to-run transition.

Background: Humans naturally transition from walking to running at a point known as the walk-to-run transition (WRT). The WRT commonly occurs at a speed of ∼2.1 m/s (m/s) or a Froude number (dimensionless value considering leg length) of 0.

Update and Novel Validation of a Pregnancy Physical Activity Questionnaire.

The aim of this study was to update and validate the Pregnancy Physical Activity Questionnaire (PPAQ), using novel and innovative accelerometer and wearable camera measures in a free-living setting, to improve the measurement performance of this method for self-reporting physical activity. A prospective cohort of 50 eligible pregnant women were enrolled in early pregnancy (mean = 14.9 weeks' gestation).

The impact of the COVID-19 pandemic on physical activity and sedentary behavior during pregnancy: a prospective study.

Background: Prior studies evaluating the impact of the COVID-19 pandemic on pregnancy physical activity (PA) have largely been limited to internet-based surveys not validated for use in pregnancy.

Methods: This study used data from the Pregnancy PA Questionnaire Validation study conducted from 2019-2021. A prospective cohort of 50 pregnant women completed the Pregnancy PA Questionnaire (PPAQ), validated for use in pregnancy, in early, mid, and late pregnancy and wore an ActiGraph GT3X-BT for seven days.

Cadence-based classification of moderate-intensity overground walking in 41- to 85-year-old adults.

Background: Walking cadence (steps/min) has emerged as a valid proxy of physical activity intensity, with consensus across numerous laboratory-based treadmill studies that ≥100 steps/min approximates absolutely defined moderate intensity (≥3 metabolic equivalents; METs). We recently reported that this cadence threshold had a classification accuracy of 73.3% for identifying moderate intensity during preferred pace overground walking in young adults.

A Transparent Method for Step Detection using an Acceleration Threshold.

Step-based metrics provide simple measures of ambulatory activity, yet device software either includes undisclosed proprietary step detection algorithms or simply do not compute step-based metrics. We aimed to develop and validate a simple algorithm to accurately detect steps across various ambulatory and non-ambulatory activities. Seventy-five adults (21-39 years) completed seven simulated activities of daily living (e.

A catalog of validity indices for step counting wearable technologies during treadmill walking: the CADENCE-adults study.

Background: Standardized validation indices (i.e., accuracy, bias, and precision) provide a comprehensive comparison of step counting wearable technologies.

Sleep Measurement Using Wrist-Worn Accelerometer Data Compared with Polysomnography.

This study determined if using alternative sleep onset (SO) definitions impacted accelerometer-derived sleep estimates compared with polysomnography (PSG). Nineteen participants (48%F) completed a 48 h visit in a home simulation laboratory. Sleep characteristics were calculated from the second night by PSG and a wrist-worn ActiGraph GT3X+ (AG).

Higher 24-h Total Movement Activity Percentile Is Associated with Better Cognitive Performance in U.S. Older Adults.

Purpose: This study aimed to assess the association of a wrist-worn, device-based metric of 24-h movement with cognitive function and subjective cognitive complaints among older adults, 60 yr and older.

Methods: This is a cross-sectional analysis of the 2011-2012 and 2013-2014 National Health and Nutrition Examination Survey (NHANES) cycles. A wrist-worn ActiGraph GT3X+ accelerometer captured total 24-h movement activity, analyzed as Monitor-Independent Movement Summary units (MIMS-units), and quantified into placement based on an age- and sex-standardized percentile.

Walking cadence (steps/min) and intensity in 61-85-year-old adults: the CADENCE-Adults study.

Background: Heuristic (i.e., evidence-based, rounded) cadences of ≥100 and ≥ 130 steps/min have consistently corresponded with absolutely-defined moderate (3 metabolic equivalents [METs]) and vigorous (6 METs) physical activity intensity, respectively, in adults 21-60 years of age.

Accelerometer Calibration: The Importance of Considering Functionality.

Purpose: To compare the accuracy and precision of a hip-worn accelerometer to predict energy cost during structured activities across motor performance and disease conditions.

Methods: 118 adults self-identifying as healthy ( = 44) and those with arthritis ( = 23), multiple sclerosis ( = 18), Parkinson's disease ( = 17), and stroke ( =18) underwent measures of motor performance and were categorized into groups: Group 1, usual; Group 2, moderate impairment; and Group 3, severe impairment. The participants completed structured activities while wearing an accelerometer and a portable metabolic measurement system.

Validation of Wearable Camera Still Images to Assess Posture in Free-Living Conditions.

Purpose: To assess the convergent validity of body worn wearable camera (WC) still-images (IMGs) for determining posture compared with activPAL (AP) classifications.

Methods: Participants (n=16, mean age 46.7±23.

A catalog of validity indices for step counting wearable technologies during treadmill walking: the CADENCE-Kids study.

Background: Wearable technologies play an important role in measuring physical activity (PA) and promoting health. Standardized validation indices (i.e.

Cadence (steps/min) and relative intensity in 21 to 60-year-olds: the CADENCE-adults study.

Background: Heuristic cadence (steps/min) thresholds of ≥100 and ≥ 130 steps/min correspond with absolutely-defined moderate (3 metabolic equivalents [METs]; 1 MET = 3.5 mL O·kg·min) and vigorous (6 METs) intensity, respectively. Scarce evidence informs cadence thresholds for relatively-defined moderate (≥ 64% heart rate maximum [HR = 220-age], ≥ 40%HR reserve [HRR = HR -HR, and ≥ 12 Rating of Perceived Exertion [RPE]); or vigorous intensity (≥ 77%HR, ≥ 60%HRR, and ≥ 14 RPE).

Identification of Latent Classes of Motor Performance in a Heterogenous Population of Adults.

Objective: To determine classes of motor performance based on community deployable motor impairment and functional tests in a heterogeneous adult population.

Design: Sixteen tests of limb-specific and whole-body measures of motor impairment and function were obtained. Linear regression analysis was used to dichotomize performance on each test as falling within or outside the age- and sex-predicted values.

Walking cadence (steps/min) and intensity in 41 to 60-year-old adults: the CADENCE-adults study.

Background: In younger adults (i.e., those < 40 years of age) a walking cadence of 100 steps/min is a consistently supported threshold indicative of absolutely-defined moderate intensity ambulation (i.

Metrics of Diabetes Risk Are Only Minimally Improved by Exercise Training in Postmenopausal Breast Cancer Survivors.

Context: Insulin resistance is a risk factor for breast cancer recurrence. How exercise training changes fasting and postglucose insulin resistance in breast cancer survivors is unknown.

Objective: To evaluate exercise-induced changes in postglucose ingestion insulin concentrations, insulin resistance, and their associations with cancer-relevant biomarkers in breast cancer survivors.

A Framework to Evaluate Devices That Assess Physical Behavior.

Body-worn devices that estimate physical behavior have tremendous potential to address key research gaps. However, there is no consensus on how devices and processing methods should be developed and evaluated, resulting in large differences in summary estimates and confusion for end users. We propose a phase-based framework for developing and evaluating devices that emphasizes robust validation studies in naturalistic conditions.

Estimating Sedentary Time from a Hip- and Wrist-Worn Accelerometer.

Purpose: This study aimed to determine the validity of existing methods to estimate sedentary behavior (SB) under free-living conditions using ActiGraph GT3X+ accelerometers (AG).

Methods: Forty-eight young (18-25 yr) adults wore an AG on the right hip and nondominant wrist and were video recorded during four 1-h sessions in free-living settings (home, community, school, and exercise). Direct observation videos were coded for postural orientation, activity type (e.

Energy Cost of Slow and Normal Gait Speeds in Low and Normally Functioning Adults.

Objective: Slow walking speed paired with increased energy cost is a strong predictor for mortality and disability in older adults but has yet to be examined in a heterogeneous sample (ie, age, sex, disease status). The aim of this study was to examine energy cost of slow and normal walking speeds among low- and normal-functioning adults.

Design: Adults aged 20-90 yrs were recruited for this study.

Elevated insulin levels following 7 days of increased sedentary time are due to lower hepatic extraction and not higher insulin secretion.

Higher insulin following sedentary behavior may be due to increased insulin secretion (IS), decreased hepatic insulin extraction (HIE), or a combination of both. Ten healthy adults completed glucose tolerance tests following 7 days of normal activity and 7 days of increased sitting. There were no differences in IS; however, HIE at 120 min after ingestion (85.

Walking cadence (steps/min) and intensity in 21-40 year olds: CADENCE-adults.

Background: Previous studies have reported that walking cadence (steps/min) is associated with absolutely-defined intensity (metabolic equivalents; METs), such that cadence-based thresholds could serve as reasonable proxy values for ambulatory intensities.

Purpose: To establish definitive heuristic (i.e.