The purposes of the study were to assess differences in physical activity levels and correlates of physical activity among overweight (‡ 85 th percentile of body mass index for their sex and age) and non-overweight (< 85th percentile) youth. The sample included 509 seventh through twelfth graders. Activity was measured by a 7-day, 46-item activity checklist. Overweight girls were more sedentary than non-overweight girls (p < .03), and non-overweight girls engaged in more vigorous physical activity than overweight girls (p < .03). For boys, there were no significant differences in activity. The regression analyses for vigorous activity yielded the largest total R2’s (R2 = .49 for overweight and R2 = .27 for non-overweight.) The significant factor for overweight youth was greater athletic coordination (p < .01). For non-overweight youth, the significant factors were greater family support (p < .05), greater peer support (p < .001), fewer barriers (p < .03), and greater athletic coordination (p < .01). Correlates of physical activity vary by weight status of young people.
Wendell C. Taylor, James F. Sallis, Marsha Dowda, Patty S. Freedson, Karen Eason and Russell R. Pate
Judith J. Prochaska, James F. Sallis, Donald J. Slymen and Thomas L. McKenzie
One mission of physical education (PE) is the promotion of enjoyable physical activity participation. PE enjoyment of 414 elementary school students (51% male, 77% Caucasian) was examined in a 3-year prospective study. Analyzed using Generalized Estimating Equations, PE enjoyment decreased significantly from the fourth to sixth grade (p < .001) and was lower among girls (p < .001) and students not in organized sports (p < .005). Ethnicity and body mass index were not significant predictors of PE enjoyment. Girls, older children, and those not on sports teams are especially dependent on PE as the setting for accruing health-related physical activity, and strategies are needed to enhance their PE enjoyment.
Thomas L. McKenzie, Kathryn J. LaMaster, James F. Sallis and Simon J. Marshall
The relationship of classroom teachers’ leisure time physical activity and their conduct of physical education classes was investigated. Eighteen 4th- and 5th-grade teachers reported on their leisure physical activity and had their physical education classes observed systematically during 4 consecutive semesters. Correlational analyses confirmed that more active teachers taught physical education differently from those that were less active. Teachers who were more active provided students with increased physical fitness activities, and the teachers themselves spent more time promoting physical fitness during lessons. The study provides some support for the hypothesis that physically active teachers provide higher quality physical education.
M. Katherine Kraft, James F. Sallis, Anne Vernez Moudon and Leslie S. Linton
Gregory J. Norman, Sandra K. Nutter, Sherry Ryan, James F. Sallis, Karen J. Calfas and Kevin Patrick
Neighborhood-level environmental features have been associated with adult physical activity and weight status, but this link has not been established for adolescents.
Community design and access to recreational facilities variables were derived using geographic information systems (GIS) for 799 adolescents (age 11 to 15 y, mean = 12.8 y, 53% girls, 43% ethnic minority). Environment variables were calculated for a 1-mile buffer around each participant’s residence. Accelerometers measured min/d of physical activity.
Number of nearby recreation facilities and number of nearby parks correlated positively with girls’ physical activity, and intersection density inversely related to girls’ physical activity. Retail floor area ratio correlated positively with boys’ physical activity. No community design or access to recreation variables were related to BMI-percentile.
There was limited evidence that both community design and access to recreation facilities variables were associated with adolescent physical activity, but additional built environment variables need to be studied that have particular relevance for youth.
Michael J. Buono, Julia J. Roby, Frank G. Micale, James F. Sallis and W. Elizabeth Shepard
The purpose of this study was to determine the validity and reliability of three of the most commonly used field tests to predict maximum oxygen uptake in children and adolescents. VO2max was directly measured during a maximal treadmill test in 90 children (10-18 yrs). Each subject also performed, in duplicate, a timed distance run (1 mile), a step test, and a submaximal cycle ergometer test. A multiple regression equation was developed with directly measured VO2max as the dependent variable and mile-run time, gender, skinfold thickness, and body weight as independent variables. The equation had a multiple R=0.84 and a standard error of estimate of 9%, or 4.3 ml/kg/min. The results suggest that when the three most commonly used field tests to predict aerobic capacity are compared in the same group of children, the timed distance run is superior in both validity and reliability.
Terence Dwyer, James F. Sallis, Leigh Blizzard, Ross Lazarus and Kimberlie Dean
The objective of this study was to examine the association of scholastic performance with physical activity and fitness of children. To do so, school ratings of scholastic ability on a five-point scale for a nationally representative sample of 7,961 Australian schoolchildren aged 7–15 years were compared with physical activity and fitness measurements. Consistently across age and sex groups, the ratings were significantly correlated with questionnaire measures of physical activity and with performance on the 1.6-kilometer run, sit-ups and push-ups challenges, 50-meter sprint, and standing long jump. There were no significant associations for physical work capacity at a heart rate of 170 (PWC170). The results are concordant with the hypothesis that physical activity enhances academic performance, but the cross-sectional nature of the observations limits causal inference, and the disparity for PWC170 gives reason to question whether the associations were due to measurement bias or residual confounding.
James F. Sallis, Wendell C. Taylor, Marsha Dowda, Patty S. Freedson and Russell R. Pate
Correlates of physical activity were examined in young people in grades 1 through 12, and analyses were conducted separately for eight age/grade and sex subgroups. Twenty-one explanatory variables were assessed by parental report. Physical activity was assessed in 781 young people via parent report, and 200 wore an accelerometer for seven days. Between 11% and 36% of parent-reported child vigorous physical activity was explained. The most consistent correlates were peer support and use of afternoon time for active rather than sedentary recreation. Peer support was the only significant correlate of objectively monitored activity in multiple subgroups.
Jorge Mota, Paula Santos, Sandra Guerra, José C. Ribeiro, José A. Duarte and James F. Sallis
The goal of this study was to validate an adapted version of the “weekly checklist” in a Portuguese population. The validity was assessed by comparing self-reports against the Computer Science and Application, Inc (CSA) monitor. The sample comprised 109 children (boys, n = 42; girls, n = 67), aged 8 to 16 years old. All subjects were volunteers from local schools (Oporto region). The weekly activity checklist was modestly (r = 0.30) but significantly (p < .01) correlated with the CSA. Girls (r = 40; p < .01) had higher correlations than boys (0.28; p < .05). When the values were analyzed by age, excluding the young subjects (<10 years old), the correlation values were slightly higher (r = 0.38; p < .01). The Portuguese version of the “weekly activity checklist” had similar reliability and validity as the original version. The measure appears to have lower validity in 8- and 9-year-old children.
Michael J. Buono, Julia J. Roby, Frank G. Micale and James F. Sallis
The Astrand-Ryhming est was modified to overcome problems of predicting V̇O2max in children. V̇O2max was measured directly during a maximal treadmill test and estimated by means of a submaximal protocol in a test group of 51 subjects ages 10–18 years. A multiple regression equation was developed with directly measured V̇O2max as the dependent variable and age, body weight, and V̇O2max estimated from the Astrand nomogram as independent variables. The validity and reliability of this equation to predict V̇O2max in children and adolescents was cross-validated. No significant difference was found between the measured V̇O2max and that estimated from the equation. The correlation coefficient between measured and estimated V̇O2max for the cross-validation group was 0.89, with a standard error of estimate of 12%. Test-retest reliability was 0.95. It was concluded that this modification of the Astrand nomogram provides a valid and reliable prediction of V̇O2max in children and adolescents.