John Schuna

John Schuna
Oregon State University | OSU · School of Biological and Population Health Sciences

PhD

About

121
Publications
19,435
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
2,285
Citations
Additional affiliations
September 2014 - present
Oregon State University
Position
  • Professor (Assistant)
July 2012 - present
Pennington Biomedical Research Center
Position
  • PostDoc Position
August 2007 - June 2012
North Dakota State University
Position
  • Research Assistant

Publications

Publications (121)
Article
Emerging evidence supports the feasibility of raising daily energy expenditure (EE) by replacing office work-related sedentary behavior with low-intensity non-exercise physical activity (PA) via workstation alternatives to the traditional office chair and desk-top computer-based combinations. The purpose of this review article is to introduce a sim...
Article
Full-text available
It remains unclear what people are attempting to communicate, in terms of objectively monitored behavior, when describing their physical activity and sedentary behavior through self-report. The purpose of this study was to examine various objectively monitored accelerometer variables (e.g., moderate-to-vigorous physical activity [MVPA], steps/day,...
Article
Previous research has reported peak vertical acceleration and peak loading rate thresholds beneficial to bone mineral density (BMD). Such thresholds are difficult to translate into meaningful recommendations for physical activity. Cadence (steps/min) is a more readily interpretable measure of ambulatory activity. To examine relationships between ca...
Article
Full-text available
Background: Standardized validation indices (i.e., accuracy, bias, and precision) provide a comprehensive comparison of step counting wearable technologies. Purpose: To expand a previously published child/youth catalog of validity indices to include adults (21-40, 41-60 and 61-85 years of age) assessed across a range of treadmill speeds (slow [0...
Article
Four-day school week schedules are being adopted with increasing frequency, particularly in rural areas. In this paper, we consider the academic implications of students in Oregon attending a four-day school week for the first time when they enter high school. We find 11th grade math achievement in 0.09 standard deviations lower among four-day scho...
Article
Step-based metrics provide simple measures of ambulatory activity, yet device software either includes undisclosed proprietary step detection algorithms or simply does not compute step-based metrics. We aimed to develop and validate a simple algorithm to accurately detect steps across various ambulatory and nonambulatory activities. Seventy-five ad...
Article
Full-text available
Background: Four-day school week (FDSW) use has increased substantially among US districts in recent years, but limited data exist on health impacts of this school schedule. This study examined associations of reduced school exposure via FDSWs with adolescent health and risk behaviors, obesity, and food security. Methods: Self-report data from 8...
Article
Full-text available
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. There is no consensus regarding similar thresholds in older adults....
Article
Full-text available
Background: Wearable technologies play an important role in measuring physical activity (PA) and promoting health. Standardized validation indices (i.e., accuracy, bias, and precision) compare performance of step counting wearable technologies in young people. Purpose: To produce a catalog of validity indices for step counting wearable technolog...
Article
Studies often rely on home locations to access built environment (BE) influences on physical activity (PA). We use GPS and accelerometer data collected for 288 individuals over a two-week period to examine eight GPS-derived BE characteristics and moderate-to-vigorous PA (MVPA) and light-to-moderate-vigorous PA (LMVPA). NDVI, parks, blue space, pede...
Article
Full-text available
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 O2·kg− 1·min− 1) and vigorous (6 METs) intensity, respectively. Scarce evidence informs cadence thresholds for relatively-defined moderate (≥ 64% heart rate maximum [HRmax = 220-...
Article
The natural transition from walking to running occurs in adults at ≅140 steps/min. It is unknown when this transition occurs in children and adolescents. The purpose of this study was to develop a model to predict age- and anthropometry-specific preferred transition cadences in individuals 6–20 years of age. Sixty-nine individuals performed sequent...
Article
Full-text available
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.e., ≥ 3 metabolic equivalents; METs). Less is known about the cadence-intensity relationship in adults of middle-age. Purpose To establish heuristic...
Article
Background: Use of 4-day school weeks (FDSWs) as a cost-saving strategy has increased substantially as many US school districts face funding declines. However, the impacts of FDSWs on physical activity exposure and related outcomes are unknown. This study examined physical education (PE) exposure and childhood obesity prevalence in 4- versus 5-day...
Article
Background: Step-counting interventions with discrepant intensity emphases may elicit different effects. Methods: A total of 120 sedentary/low-active, postmenopausal women were randomly assigned to one of the following 3 groups: (1) 10,000 steps per day (with no emphasis on walking intensity/speed/cadence; basic intervention, 49 completers), (2)...
Article
Objectives The scaling of structural components to body size is well studied in mammals, although comparable human observations in a large and diverse sample are lacking. The current study aimed to fill this gap by examining the scaling relationships between total body (TB) and regional bone and skeletal muscle (SM) mass with body size, as defined...
Article
BACKGROUND Classroom‐based physical activity (CBPA) breaks are a common strategy to increase elementary school children's physical activity (PA) levels. There is limited research examining how teacher‐level factors impact teacher implementation of CBPA breaks. In this study, we assessed the relationship of teacher‐level factors with teacher use of...
Article
Walking cadence (steps per minute) is associated with the intensity of ambulatory behavior. This analysis provides normative values for peak 30-min cadence, an indicator of "natural best effort" during free-living behavior. A sample of 1,196 older adults (aged from 60 to 85+) with accelerometer data from the National Health and Nutrition Examinatio...
Article
Full-text available
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., evidence-based, practical, rounded) threshol...
Article
Background: Active workstations offer the potential for augmenting energy expenditure (EE) in sedentary occupations. However, comparisons of EE during pedal and treadmill desk usage at self-selected intensities are lacking. Methods: A sample of 16 adult participants (8 men and 8 women; 33.9 [7.1] y, 22.5 [2.7] kg/m2) employed in sedentary occupa...
Article
Full-text available
The purpose of this study was to compare changes in diet and daily physical activity (PA) in high school (HS) soccer players who participated in either a two-year obesity prevention intervention or comparison group, while controlling for sex, race/ethnicity, and socioeconomic status. Participants (n = 388; females = 58%; Latino = 38%; 15.3 ± 1.1 ye...
Article
Background: Active workstation alternatives (e.g., treadmill desks and pedal desks) have the potential to elevate workplace energy expenditure by replacing occupational sedentary behavior with opportunities to generate low-intensity non-exercise physical activity, but only to the extent that workers find them acceptable and congruent with their pr...
Article
Full-text available
Background Cadence (steps/min) may be a reasonable proxy-indicator of ambulatory intensity. A summary of current evidence is needed for cadence-based metrics supporting benchmark (standard or point of reference) and threshold (minimums associated with desired outcomes) values that are informed by a systematic process. Objective To review how fast,...
Article
The purpose of this study was to test whether estimates of bedtime, wake time, and sleep period time (SPT) were comparable between an automated algorithm (ALG) applied to waist-worn accelerometry data and a sleep log (LOG), in an adult sample. A total of 104 participants were asked to log evening bedtime and morning wake time and wear an ActiGraph...
Article
Full-text available
Background Steps/day is widely utilized to estimate the total volume of ambulatory activity, but it does not directly reflect intensity, a central tenet of public health guidelines. Cadence (steps/min) represents an overlooked opportunity to describe the intensity of ambulatory activity. We sought to establish thresholds linking directly observed c...
Poster
Sedentary behaviors are highly prevalent, even in children and adolescents. Zero cadence (steps/min) determined using wearable devices may be a suitable proxy measure of seated sedentary behaviors in children and adolescents since theoretically no steps should be produced or detected in this position. PURPOSE: To determine the capability of acceler...
Poster
BACKGROUND: Cadence (steps/min) has been used to infer intensity of adult ambulatory activity, an important constituent of public health physical activity guidelines. PURPOSE: To identify cadence cut-points linking visually observed cadence with absolutely-defined moderate-intensity across in children and adolescents. METHODS:123 participants betwe...
Presentation
BACKGROUND: Previous studies have established the strong correlation between cadence (steps/min) and intensity, with 100 steps/min emerging as a reasonable heuristic value (i.e., evidence-based, practical, rounded cut point) representative of moderate-intensity ambulation. PURPOSE: To determine the classification accuracy of cadence cut points for...
Poster
BACKGROUND: Various accelerometer cut points related to moderate-intensity have been proposed, thereby complicating physical activity assessment. In contrast, there is remarkable consistency supporting a cadence-based heuristic cut point of 100 steps/min for classifying moderate-intensity ambulation (3 metabolic equivalents [METs]). PURPOSE: To com...
Poster
Purpose: To compare cadence obtained from waist and wrist accelerometer attachment sites (relative to visually counted step criterion standard) in treadmill and simulated activities of daily living. Methods: 40 men and 40 women (age=30.5±5.9 years, BMI=24.8±3.4 kg/m2) concurrently wore Actigraph GT9XLink accelerometers at their waist and non-domina...
Article
Full-text available
Purpose: To catalog the relationships between step-based accelerometer metrics indicative of physical activity volume (steps/day, adjusted to a pedometer scale), intensity (mean steps/min from the highest, not necessarily consecutive, minutes in a day; peak 30-min cadence) and sedentary behavior (percent time at zero cadence relative to wear time;...
Article
Purpose: To compare clinical and free-living walking cadence in school-age children, and examine how allometric scaling of leg length variability affects objective ambulatory activity assessment. Methods: 375 children (154 boys, 221 girls; 9-11 years) completed GAITRite-determined slow, normal, and fast walks and wore accelerometers for 1 week....
Article
Background: Energy expenditure (EE) estimates for a broad age range of youth performing a variety of activities are needed. Methods: 106 participants (6-18 years) completed 6 free-living activities (seated rest, movie watching, coloring, stair climbing, basketball dribbling, jumping jacks) and up to 9 treadmill walking bouts (13.4 to 120.7 m/min...
Article
Participants: included 84 university students (33 cadets and 51 non-cadets) who each wore an accelerometer for five consecutive days to estimate moderate and vigorous physical activity (MVPA). A 2X2 mixed model ANOVA was used to examine within and between group differences in MVPA on training and non-training days. This analysis was repeated after...
Conference Paper
Cadence (steps/min) is strongly correlated with intensity of effort defined as metabolic cost in adults such that 100 steps/min has been consistently considered a reasonable heuristic value representative of moderate-intensity activity (3 metabolic equivalents [METs]). No studies have yet looked at visually tallied (i.e., the criterion standard) ca...
Conference Paper
Full-text available
There are limited reports evaluating accuracy in free-living activities among children and adolescents. PURPOSE: To evaluate step counting accuracy of the ActiGraph GT3X+ accelerometer in waist- and wrist-worn locations during simulated free-living activities among children and adolescents. METHODS: 123 children and adolescents (6-20 years) perform...
Article
Full-text available
The purpose of the study was to conduct an evaluation of an unstructured afterschool physical activity (PA) programme (Keep it Moving!; KIM) in an ethnically diverse and low socio-economic status (SES) school district. PA of students in 3rd-5th grades (N = 205) at four elementary schools were assessed during spring 2012. An ActiGraph accelerometer...
Article
Full-text available
Background: This investigation evaluated seasonal changes in preschoolers' (3-5 years) sedentary time and physical activity (PA) during childcare. Methods: Sixty-two children from 4 preschools in Fargo, North Dakota had their sedentary behavior and PA objectively assessed during 2 separate weeks of childcare. Children wore accelerometers for 5 cons...
Article
Full-text available
This study tested the validity of revolutions per minute (RPM) measurements from the Pennington Pedal Desk™. Forty-four participants (73 % female; 39 ± 11.4 years-old; BMI 25.8 ± 5.5 kg/m 2 [mean ± SD]) completed a standardized trial consisting of guided computer tasks while using a pedal desk for approximately 20 min. Measures of RPM were concurre...
Article
Full-text available
Body mass index (BMI) is now the most widely used measure of adiposity on a global scale. Nevertheless, intense discussion centers on the appropriateness of BMI as a phenotypic marker of adiposity across populations differing in race and ethnicity. BMI-adiposity relations appear to vary significantly across race/ethnic groups, but a collective crit...