Skip M. Williams

Concurrent validation of the Actigraph gt3x+, Polar Active accelerometer, Omron HJ-720 and Yamax Digiwalker SW-701 pedometer step counts in lab-based and free-living settings

Abstract Activity monitors are frequently used to assess activity in many settings. But as technology advances, so do the mechanisms used to estimate activity causing a continuous need to validate newly developed monitors. The purpose of this study was to examine the step count validity of the Yamax Digiwalker SW-701 pedometer (YX), Omron HJ-720 T pedometer (OP), Polar Active accelerometer (PAC) and Actigraph gt3x+ accelerometer (AG) under controlled and free-living conditions. Participants completed five stages of treadmill walking (n = 43) and a subset of these completed a 3-day free-living wear period (n = 37). Manually counted (MC) steps provided a criterion measure for treadmill walking, whereas the comparative measure during free-living was the YX. During treadmill walking, the OP was the most accurate monitor across all speeds (±1.1% of MC steps), while the PAC underestimated steps by 6.7–16.0% per stage. During free-living, the OP and AG counted 97.5% and 98.5% of YX steps, respectively. The PAC overestimated steps by 44.0%, or 5,265 steps per day. The Omron pedometer seems to provide the most reliable and valid estimate of steps taken, as it was the best performer under lab-based conditions and provided comparable results to the YX in free-living. Future studies should consider these monitors in additional populations and settings.

Top 10 research questions related to physical activity and bone health in children and adolescents.

Evidence strongly supports a positive, causal effect of physical activity on bone strength and suggests long-term benefits of childhood physical activity to the prevention of osteoporosis. The contribution of healthy bone development in youth is likely to be as important to fracture prevention as the amount of late adulthood bone loss. Families, schools (particularly physical education), and communities are key settings for health promotion focused on bone-enhancing physical activity. However, little research has explored the topic of health promotion and physical education as they pertain to bone health, so best practices are not known. Based on our understanding of the literature, we present the top 10 research questions in health promotion and physical education that should be answered to advance bone-enhancing physical activity in children and adolescents.

Should Secondary Physical Education Be Coeducational or Single-Sex?

6 JOPERD • Volume 79 No. 2 • February 2008 Physical education in public and private schools in the United States remained primarily separated by sex until the passage of Title IX in 1972. Under provisions of Title IX, schools were required to provide both boys and girls with the same opportunities to participate in all physical education activities. The only times considered appropriate for boys and girls to be separated was for class competition during contact sports such as wrestling, football, and hockey. As school districts started coming into compliance with Title IX, the inevitable question began to be asked, “Is coeducational or single-sex physical education the best learning environment for all students?” Although one purpose of Title IX legislation was to eliminate gender inequity in physical education, research has indicated that inequitable teaching behaviors have continued and that these behaviors have limited the learning potential of both boys and girls (Dunbar & O’Sullivan, 1986; Griffi n, 1984; Treanor, Graber, Housner, & Wiegand, 1998). This has led some to call for occasional, singlesex groupings within coeducational physical education (Gabbei, 2004), or a return to single-sex physical education (Scraton, 1993). Recently, the U.S. Department of Education (2006) made changes to alleviate restrictions on single-sex classes. These changes have provided greater fl exibility for schools to be able to offer single-sex classes. The changes also require single-sex classes to be evaluated every two years to make sure that males and females are being treated equitably. We have found that nearly half of the middle or junior high schools in which we have placed student teachers have taken advantage of the Department of Education’s alleviated restrictions to switch back to single-sex physical education classes. In our view, this action is as premature as the sudden switch to coeducational classes was in the 1970s. Educational reform should be based on a heavy dose of supporting research. After reform has been made, it should be carefully assessed to determine whether or not it is meeting its intended purpose. The move to coeducational classes in physical education was not supported by an appropriate amount of research, and the current trend towards switching back to single-sex physical education also lacks support. If we solely examine the limited available research, it is diffi cult to answer the question of whether coeducational or single-sex physical education provides the best learning environment in secondary physical education. Relatively few studies have been published, and their conclusions in support of either coeducational or singlesex physical education have often varied based on the outcome(s) of interest and grade levels investigated. The studies that have been conducted have focused primarily on teacher and student perceptions, student-teacher interactions and participation opportunities, and student physical activity levels in coeducational and singlesex physical education.

EFFECT OF A CORE CONDITIONING INTERVENTION ON TESTS OF TRUNK MUSCULAR ENDURANCE IN SCHOOL-AGED CHILDREN

Abstract Allen, BA, Hannon, JC, Burns, RD, and Williams, SM. Effect of a core conditioning intervention on tests of trunk muscular endurance in school-aged children. J Strength Cond Res 28(7): 2063–2070, 2014—Trunk and core muscular development has been advocated to increase athletic performance and for maintenance of musculoskeletal health, especially related to the prevention of low back pain (LBP). The purpose of this study was to examine the effects of a simple core conditioning routine on tests of trunk and core muscular endurance in school-aged children. Participants included 164 students (86 girls, 78 boys; mean age, 11.5 ± 2.5 years) recruited from a grade school in a metropolitan area located in the southwestern United States. Students performed an equipment-free, moderate-to-high intensity, dynamic core conditioning warm-up routine once a week for a period of 6 weeks during the start of their physical education classes. The intervention consisted of 10 different dynamic core conditioning exercises performed at a 30-second duration per exercise totaling 5 minutes per session. Pre- and post-assessments of muscular endurance consisted of 5 different trunk and core muscular endurance tests: Parallel Roman Chair Dynamic Back Extension, Prone Plank, Lateral Plank, Dynamic Curl-Up, and Static Curl-up. A generalized estimation equation was used to analyze differences in pre- and post-intervention muscular fitness assessments controlling for gender and grade level. Analysis of the data revealed significant increases in muscular fitness test performance for each of the 5 measured outcomes (p < 0.001). Because risk factors of LBP are thought to commence during childhood, results of this study suggest that it may be desirable for children and adolescents to perform moderate-to-high intensity dynamic core exercises during physical education warm-up to improve trunk and core muscular endurance.

Physical Education Homework That Involves the Family.

the recommended levels of physical activity (PA; U.S. Department of Health and Human Services [USDHHS], 2008). It has been well documented that adults have less leisure time to devote to PA than a typical adolescent does. Adolescents have an abundant amount of leisure time that is typically spent using some sort of electronic device (Sherman, 2000). It is well known that PA declines among children and adolescents over time (Kimm et al., 2002; Tomkinson, Leger, Olds, & Cazorla, 2003). Increasing the amount of daily PA has the greatest potential to increase health benefi ts among adults and adolescents. By Skip M. Williams and James C. Hannon Physical Education

Fitness knowledge, cardiorespiratory endurance and body composition of high school students

Summary Study aim: The purpose of this study was to determine if high school physical education seniors’ health-related fitness knowledge is related to their aerobic capacity and body composition. Material and methods: The FitSmart test assessed students (n = 171) health-related fitness knowledge. Aerobic capacity was calculated based on the students PACER score. Body Composition was measured using the Tanita TBF 300A body composition analyzer. Results: Aerobic fitness was a statistically significant predictor of exam score (β = 0.563, p < 0.001), but percent body fat was not (β = 0.185, p =0.074). Comparing the health-related fitness exam scores by the FITNESSGRAM classification system, students who were classified as Very Lean and High Risk for body composition had lower exam scores than those classified in the healthy fitness zone. Conclusions: The results confirmed previous findings that students have inadequate health-related fitness knowledge. Furthermore, the study extends these findings by identifying some associations of percent body fat and estimated VO2max to health-related fitness knowledge.

Acute and Session Ratings of Perceived Exertion in a Physical Education Setting

A commonly stated rationale for examining the use of ratings of perceived exertion with youth is its potential value as an assessment of intensity in physical education settings. The purpose of this study was to examine the relation between ratings of perceived exertion and heart rate in a natural physical education setting. Sixth through eighth grade students performed cardiovascular and muscle endurance circuits and then recorded ratings and heart rate. It was hypothesized that, similar to laboratory studies, strong positive correlations would be seen between heart rate and ratings of perceived exertion, which would provide additional support for the use of ratings of perceived exertion in physical education. However, only low to moderate correlations were found. When data collection occurs in a natural physical education setting, there are challenges that may result in poor correlational results between variables such as heart rate and perceived exertion that demonstrate strong relationships when examined in laboratory settings.

Step counts and self-reported physical activity among upper elementary school students vary with aerobic fitness

Summary Study aim: The purpose of this study was to examine if step-counts during PE and self-reported PA of elementary grade students varied based on the aerobic capacity. Material and methods: Ninety elementary physical education students, enrolled in the 4th and 5th grade, from one elementary school in the Midwestern USA participated. Each participant completed the Physical Activity Questionnaire for Children (PAQ-C), wore a pedometer in PE to measure steps taken, and completed the PACER aerobic fitness test. A multiple regression analysis was conducted to determine the relationship between steps taken by students and PAQ-C score in predicting aerobic capacity as measured through the PACER test. Results: Average steps significantly predicted PACER laps (β = 0.48, p < 0.01), as did the PAQ-C (β = 0.28, p < 0.001). For males, average steps significantly predicted PACER laps (β = 0.48 p < 0.01), while the PAQ-C and the PACER beta coefficients were not statistically significant (β = 0.14, p = 0.30). Results for females indicated average steps significantly predicted PACER laps (β = 0.38, p < 0.01), as did the PAQ-C (β = 0.46, p < 0.001). Conclusion: Results from this study indicate that student steps taken during PE and self-report PA has an association with students’ completed PACER laps.