This study examined the relationship between heart rate (HR) as a measure of physiological strain and ratings of perceived exertion (RPE) in 193 children (mean age = 11 yrs) and 188 adults (mean age = 36 yrs) during submaximal cycle ergometry. Two methods of correlating HR and RPE were compared. Computing correlations (r) for each individual’s data and then taking the group mean produced very high rs, ranging from 0.92 to 0.95. Correlating HR and RPE for the entire group at all powers simultaneously produced much lower rs, ranging from 0.63 to 0.65. Correlations were essentially the same for children and adults, and there was no evidence of a practice effect. The results indicated that (a) children in this age group were as capable of expressing RPE as adults, and (b) absolute levels of perceived exertion were not predictive of physiological strain (as indicated by heart rate).
Mary C. Gillach, James F. Sallis, Michael J. Buono, Patricia Patterson and Philip R. Nader
Nefertiti Durant, Jacqueline Kerr, Sion Kim Harris, Brian E. Saelens, Gregory J. Norman and James F. Sallis
Few studies have explored barriers to physical activity in parks and streets among children, adolescents, and their parents. The purpose of this article is to evaluate the psychometric properties of a new survey of barriers to physical activity in neighborhood parks and streets. Adolescents and parents of children and adolescents completed surveys twice. Two barrier subscales (environment and safety) emerged that applied to both locations and all participant groups. Results generally supported acceptable, internal consistency as well as construct validity, but test-retest reliabilities were lower than desired. These scales may be used to improve understanding of perceptions of barriers to physical activity in neighborhood parks and streets, but further development is needed.
Ugo Lachapelle, Larry Frank, Brian E. Saelens, James F. Sallis and Terry L. Conway
Most public transit users walk to and from transit. We analyzed the relationship between transit commuting and objectively measured physical activity.
Adults aged 20 to 65 working outside the home (n = 1237) were randomly selected from neighborhoods in Seattle and Baltimore regions. Neighborhoods had high or low median income and high or low mean walkability. Mean daily minutes of accelerometer-measured moderate-intensity physical activity (MPA) were regressed on frequency of commuting by transit and neighborhood walkability, adjusting for demographic factors and enjoyment of physical activity. Interaction terms and stratification were used to assess moderating effect of walkability on the relation between transit commuting and MPA. Associations between transit commuting and self-reported days walked to destinations near home and work were assessed using Chi Square tests.
Regardless of neighborhood walkability, those commuting by transit accumulated more MPA (approximately 5 to 10 minutes) and walked more to services and destinations near home and near the workplace than transit nonusers. Enjoyment of physical activity was not associated with more transit commute, nor did it confound the relationships between MPA and commuting.
Investments in infrastructure and service to promote commuting by transit could contribute to increased physical activity and improved health.
Guadalupe X. Ayala, Amy Gammelgard, James F. Sallis and John. P. Elder
Studies have examined the association between work-related characteristics and physical activity participation; however few studies include U.S. Latinos.
Six hundred and seventy two Latino adults of San Diego County were randomly sampled and surveyed to assess their health behaviors in the fall of 2006. Analyses were conducted with 633 respondents with physical activity data (94% of sample), examining the extent to which job category and hours worked per week were associated with 4 domains of physical activity defined by MET-minutes per week using the long IPAQ.
Multivariate analysis of variance models were computed. After adjusting for covariates, occupational MET-minutes per week were associated with job category and hours worked per week, such that blue collar workers expended more MET-minutes per week than white collar or nonworkers, and those who worked 20 hours a week or less expended less occupational physical activity compared with those who worked more than 20 hours per week. In addition, nonworkers reported expending more household MET-minutes per week than blue collar or white collar workers.
Efforts are needed to increase the physical activity levels of Mexican immigrants/Mexican-Americans, with interventions designed in consideration of the individual’s work status.
Dori E. Rosenberg, Gregory J. Norman, Nicole Wagner, Kevin Patrick, Karen J. Calfas and James F. Sallis
Sedentary behavior is related to obesity, but measures of sedentary behaviors are lacking for adults. The purpose of this study was to examine the reliability and validity of the Sedentary Behavior Questionnaire (SBQ) among overweight adults.
Participants were 49 adults for the 2 week test-retest reliability study (67% female, 53% white, mean age = 20) and 401 overweight women (mean age = 41, 61% white) and 441 overweight men (mean age = 44, 81% white) for the validity study. The SBQ consisted of reports of time spent in 9 sedentary behaviors. Outcomes for validity included accelerometer measured inactivity, sitting time (International Physical Activity Questionnaire), and BMI. Intraclass correlation coefficients (ICCs) assessed reliability and partial correlations assessed validity.
ICCs were acceptable for all items and the total scale (range = .51–.93). For men, there were significant relationships of SBQ items with IPAQ sitting time and BMI. For women, there were relationships between the SBQ and accelerometer inactivity minutes, IPAQ sitting time, and BMI.
The SBQ has acceptable measurement properties for use among overweight adults. Specific measures of sedentary behavior should be included in studies and population surveillance.
Dori E. Rosenberg, Jacqueline Kerr, James F. Sallis, Gregory J. Norman, Karen Calfas and Kevin Patrick
The authors tested the feasibility and acceptability, and explored the outcomes, of 2 walking interventions based on ecological models among older adults living in retirement communities. An enhanced intervention (EI) was compared with a standard walking intervention (SI) among residents in 4 retirement facilities (N = 87 at baseline; mean age = 84.1 yr). All participants received a walking intervention including pedometers, printed materials, and biweekly group sessions. EI participants also received phone counseling and environmental-awareness components. Measures included pedometer step counts, activities of daily living, environment-related variables, physical function, depression, cognitive function, satisfaction, and adherence. Results indicated improvements among the total sample for step counts, neighborhood barriers, cognitive function, and satisfaction with walking opportunities. Satisfaction and adherence were high. Both walking interventions were feasible to implement among facility-dwelling older adults. Future studies can build on this multilevel approach.
Kelli L. Cain, James F. Sallis, Terry L. Conway, Delfien Van Dyck and Lynn Calhoon
In 2005, investigators convened by the National Cancer Institute recommended development of standardized protocols for accelerometer use and reporting decision rules in articles. A literature review was conducted to document accelerometer methods and decision rule reporting in youth physical activity articles from 2005−2010.
Nine electronic databases identified 273 articles that measured physical activity and/or sedentary behavior using the most-used brand of accelerometer (ActiGraph). Six key methods were summarized by age group (preschool, children, and adolescents) and trends over time were examined.
Studies using accelerometers more than doubled from 2005−2010. Methods included 2 ActiGraph models, 6 epoch lengths, 6 nonwear definitions, 13 valid day definitions, 8 minimum wearing day thresholds, 12 moderate-intensity physical activity cut points, and 11 sedentary cut points. Child studies showed the most variation in methods and a trend toward more variability in cut points over time. Decision rule reporting improved, but only 54% of papers reported on all methods.
The increasing diversity of methods used to process and score accelerometer data for youth precludes comparison of results across studies. Decision rule reporting is inconsistent, and trends indicate declining standardization of methods. A methodological research agenda and consensus process are proposed.
Carrie M. Geremia, Kelli L. Cain, Terry L. Conway, James F. Sallis and Brian E. Saelens
Background: Assessment of park characteristics that may support physical activity (PA) can guide the design of more activity-supportive parks. Direct-observation measures are seldom used due to time and resource restraints. Methods: The authors developed shortened versions of the original Environmental Assessment of Public Recreation Spaces (EAPRS) tool and tested their construct validity by comparing scores from 40 parks in San Diego, CA to observe park use and PA. Results: PA elements were positively associated with park use and park PA across all versions, with the highest correlations for trails (.45 for use and .51 for PA using EAPRS-Original; .57 use and .62 PA using Abbreviated; and .38 use and .43 PA using Mini). Presence of amenities, using Abbreviated and Mini versions, was correlated with park use (.71, .64) and PA (.67, .59). The overall park quality score using Abbreviated and Mini had similar correlations (adjusted for park size) with park use (.74, .72) and PA (.72, .70) as EAPRS-Original (.71 use and .73 PA). Conclusion: In all 3 versions, EAPRS overall park scores were strongly related to observed park use and PA. Shorter versions of EAPRS make it more feasible to use park observations in research and practice.
Dori E. Rosenberg, Fiona C. Bull, Alison L. Marshall, James F. Sallis and Adrian E. Bauman
This study explored definitions of sedentary behavior and examined the relationship between sitting time and physical inactivity using the sitting items from the International Physical Activity Questionnaire (IPAQ).
Participants (N = 289, 44.6% male, mean age = 35.93) from 3 countries completed self-administered long- and short-IPAQ sitting items. Participants wore accelero-meters; were classified as inactive (no leisure-time activity), insufficiently active, or meeting recommendations; and were classified into tertiles of sitting behavior.
Reliability of sitting time was acceptable for men and women. Correlations between total sitting and accelerometer counts/min <100 were significant for both long (r = .33) and short (r = .34) forms. There was no agreement between tertiles of sitting and the inactivity category (kappa = .02, P = .68).
Sedentary behavior should be explicitly measured in population surveillance and research instead of being defined by lack of physical activity.
Charles F. Morgan, Thomas L. McKenzie, James F. Sallis, Shelia L. Broyles, Michelle M. Zive and Philip R. Nader
We examined associations of demographic/biological, psychological, social, and environmental variables with two different measures (self-reported and accelerometer) of physical activity (PA) in Mexican-American (56 boys; 64 girls) and European-American (49 boys; 45 girls) children (mean age = 12.1 years). Among 32 potential correlates, 4 gender and 16 ethnic differences were found. Percent of variance explained from 3% to 24% for self-reported PA and from 7% to 16% for accelerometer-measured PA. Physical self-perception was the only variable with a significant association across all subgroups and both measures. Less favorable levels of psychosocial variables among Mexican-Americans may explain ethnic differences in PA.