Physiological Effects of the BOKS Before-School Physical Activity Program for Preadolescent Youth

Physiological Effects of the BOKS Before-School Physical Activity Program for Preadolescent Youth Wayne L. Westcott1*, Kim Puhala2, Amanda Colligan3, Rita LaRosa Loud4 and Robert Cobbett4 1Director of Exercise Science, Quincy College, Quincy, MA, USA 2Vice-President, Institutional Research and Assessment, Quincy College, MA, USA 3Survey Analyst, Institutional Research and Assessment, Quincy College, MA, USA 4Exercise Science Faculty, Quincy College, MA, USA Journal of Exercise, Sports & Orthopedics Open Access Research Article


Introduction
Approximately one in three elementary school students in the United States is overweight or obese [1]. Between 1980 and 2010, the prevalence of obesity in 6 to 11 year old boys and girls increased almost threefold from 6.5% to 18.0% [1]. Within this including elevated blood pressure, undesirable blood lipid been associated with metabolic risk in preadolescents [5]. Other researchers [6] have reported an inverse relationship between

Methods
This study was approved by the Institutional Review Board of Quincy College, and by the Weymouth, Massachusetts public school system in which the research was conducted. Two similar elementary schools were chosen by the Weymouth public school system administration for inclusion in the study. Students in Kindergarten through fourth grade are eligible to participate in the BOKS before-school exercise program, and children from all of these grade levels were selected by administrators of the two participating elementary schools for the study assessments. One school did not offer the BOKS before-school physical activity program and served as the control group. The other school provided the BOKS before-school physical activity program for 50 minutes, three days each week, and served as the exercise group. This elementary school had conducted the BOKS beforeschool physical activity program the previous year with the same lead instructor. Students in both elementary schools participated in similar physical education programs directed by full-time physical education teachers employed by the Weymouth public school system.
We decided to conduct the physical assessments at the beginning and end of a 9-week period as this was within the 8 to 21] and accommodated the Fall schedule of the Weymouth elementary schools. The before-school exercise program was directed by parent volunteers who completed training courses a 6.5-hour workshop and a demonstrated understanding of the BOKS physical activities, educational curriculum, instructional methods, and class management.
The BOKS program was conducted in accordance with dozens of lesson plans that involved a variety of continuous and intermittent physical activities, including group games, running relays, locomotor movements, body weight exercises, and controlled stretches. During each cool-down segment, the students listened to a brief, age-appropriate presentation sleep. Parents typically car pooled their children to the school playground or gymnasium where they checked-in and did warmup exercises prior to the group activity session.

Participants
The study subjects included a total of 112 elementary school students in grades K-4. These participants included 81 elementary school students (46 males, 35 females; mean age 7.6 ± 1.40 years) who participated in the BOKS before-school exercise program and 31 elementary school students (24 males, 7 females; mean age 8.7 ± 0 .75 years) who did not participate in the BOKS before-school exercise program. Students in the two participating elementary schools were from similar socioeconomic backgrounds, with an average of 83% white and 17% non-white children. All of the study subjects performed their normal daily activities and participated in their scheduled school physical education classes. P < 0.05) from the exercise group in age, height, body weight (kg), percent fat, lean weight (kg), muscle strength (kg), and aerobic performance (seconds).
Due to the variability of these characteristics, a Mann-Whitney difference between groups. The baseline physical characteristics for the 112 study participants are presented in Table 1.

Procedures
The role of our research team was strictly to assess selected physical characteristics of the exercise group and control group in a separate area away from the gymnasium and playground. The investigators had no involvement in the exercise program, and no interaction with the BOKS instructors during the physical activity sessions. The investigators interacted with the children investigators were uniformly friendly and encouraging, and addressed each student by name, as they all wore name tags.

Assessments
All of the assessments were conducted at the beginning and end of the 9-week study period between October 16, 2014 and December 19, 2014. All of the assessments were performed by 400 meter runs which were administered by the school physical education specialists. Subject assessments included height, body weight, percent body fat, fat weight, lean weight, muscle strength, Height and body weight were obtained to the nearest onekg), respectively, on a manually adjusted balance scale with a

Data Analysis
Normality tests were conducted on all variables used in the data analyses. Due to the variability in the sample of elementary school students (grades K-4), few variables demonstrated normal distribution as evident from Shapiro-Wilk tests (P > 0.05). As a result, nonparametric statistical analyses were used to determine percent body fat, fat weight, lean weight, muscle strength, joint differences was established at P = 0.05. All data analyses were performed using IBM SPSS Statistics 20 software.
The Mann-Whitney test was performed on the average change between pre and post-treatment measurements of height, body weight, percent body fat, fat weight, lean weight, muscle difference in the average change in these characteristics between the exercise and control groups.
Linear regressions were also performed to determine if of overall average change in measures of height, body weight, percent body fat, fat weight, lean weight, muscle strength, joint were conducted using the Kolmogorov-Smirnov tests. Because of the non-normal distribution of the independent variables, Kolmogorov-Smirnov tests were used rather than Shapiro-Wilk tests. Residuals of the dependent variables -the changes in height, body weight, percent body fat, fat weight, lean weight, The linear regression was able to control for all pre-treatment measurements, which was important given that the two groups weight, lean weight, and muscle strength. Age and gender were also added as control measures (Table 2).

Results
There were no injuries reported by any of the study participants. Three students moved out of the school district, and 13 children were not available for the scheduled retesting sessions due to personal illness or family vacation, resulting in a total of 112 students who completed both of the study assessments. Mean changes in height, body weight, percent body aerobic performance for the exercise and control groups are presented in Table 3.
Height between the two study groups for changes in height (P=0.083). Subjects in the control group experienced a mean height increase of 0.81 cm and participants in the exercise group experienced a mean height increase of 1.40 cm. Regression analyses demonstrated that when controlling for baseline with participation in the BOKS exercise program.

Body Weight
two study groups for changes in body weight (P = 0.090). The control subjects experienced a mean body weight gain of 0.45 kg, and the exercise participants experienced a mean body weight gain of 0.86 kg over the 9-week study period. Body weight was exercise program, even when controlling for other baseline measurements.

Percent Body Fat
The two study changes in percent body fat. The exercise group experienced a

Aerobic Performance
The average change between the two study groups for P = 0.046). The mean 400 meter run time of the control group increased by 2.81 seconds, indicating a slower run performance. The mean 400 run time of the exercise group decreased by 1.13 seconds, indicating a faster practical effect (r = -0.20).
Linear regression demonstrated that when controlling for between the average change in aerobic performance and participation in the BOKS exercise program (P = 0.011). After controlling for these characteristics, participation in the BOKS exercise program was associated with an 8.44-second reduction in 400 meter run time.

Discussion
The control group of elementary-aged children who did not participate in a before-school group exercise program or aerobic performance over the 9-week study period. The elementary-aged children who did participate in a before-school in percent body fat, fat weight, and aerobic performance.
With respect to body weight, the 0.45 kg weight gain experienced by the control group and the 0.86 kg weight gain experienced by the exercise group were not statistically different. difference in percent body fat changes indicated that the  exercise program had a positive impact on the participants' body composition. The exercise group's adjusted 1.47% improvement in percent body fat compared favorably to the 1.1% improvement in percent body fat experienced by non-dieting adult participants Given the threefold increase in childhood obesity for 6 to body composition in elementary-aged youth. Body composition exclusive components, fat weight and lean weight. Percent body fat can be improved by reducing fat weight, increasing lean weight, or both. Although the lean weight gain experienced by the BOKS participants was not attributable to the exercise program, the adjusted 0.40 kg reduction in fat weight was activity program. The BOKS exercise program participants' that experienced by youth who completed a standard physical However, preadolescent boys and girls in a previous study who participated in an eight-week after-school strength training The exercise group showed more improvement than the control group on the biceps strength assessment (0.70 kg vs. 0.12 the MicroFit system biceps strength test is a valid and reliable from a general physical activity program that did not include may have occurred in the muscles that were primarily involved in push-ups), but strength improvements in these muscles would observed strength changes. All of the physical activities were performed dynamically through relatively large movement ranges, but the MicroFit system biceps test assessed muscle associated with the BOKS program, as many of the physical activities featured a variety of dynamic stretches and full-range exercise movements. It is suggested that a few static stretches performed during the cool-down section of each BOKS class Adult aerobic performance is assessed by graduated exercise as the 1.5 mile run and the 3-minute step the 400 meter run is a more appropriate assessment of aerobic performance for elementary school boys and girls, as the 1.5 mile run is too long and the 3-minute step test heart rate monitoring is too challenging for young children. Although largely an anaerobic activity for high school students, the 400 meter run times performed by the study participants (ages 5 to 10 years) were over 2 minutes, indicating a relatively high aerobic component. Unlike the control group participants who did not decrease their run time, the BOKS exercise program participants' 400 meter run time was about 2 seconds faster than their pre-training time. When controlling the baseline characteristics, as well as gender P < 0.05). We also learned that percent body fat, fat weight and initial run school exercise program was effective for improving percent body fat, decreasing fat weight, and increasing aerobic performance.
group and the control group for changes in height, bodyweight, plausible that more high-effort strength exercises could generate greater improvements in lean weight and muscle strength, we recommend a cautious approach to program revisions.
Presently, the BOKS curriculum features a commendable blend of purposeful physical activity, cooperative games, and positive interactions that enable elementary school children of varying ages to enjoy exercising together on an every-other day basis throughout the school year. The BOKS program has been uniformly well-received by students, parents, teachers, and administrators, as indicated by the increasing participation of age-eligible children and volunteer instructors, as well as scheduled expansion of the program to other elementary schools students reported that they would sign up for another BOKS session, 98% of 573 parents reported that they would re-enroll their child/children in another BOKS session, and 72% of 226 teachers reported that students in the BOKS program were performing better in class. It is therefore suggested that changes in the activity protocol be made slowly and progressively, while maintaining as much fun and games emphasis as possible.
Within these parameters, we would make a case for more muscle strengthening exercises in the BOKS program, incorporating both bodyweight (internal resistance) and resistance bands (external resistance). Although preadolescent strength training studies have demonstrated excellent results elementary school gymnasiums. It is therefore recommended that a variety of resistance band exercises be added to the BOKS physical activity program, as resistance bands are relatively safe, versatile, inexpensive, and easy to store in small spaces. Importantly, resistance band training has been associated with density in pre-adolescents. Nine-year old girls who performed standard dumbbell and resistance band exercises increased their bone mineral density four times (6.2% vs 1.4%) as much as nineyear old girls who did not do strength training over the 10-month development is established during the preadolescent years, the recommended that children's physical activity programs include age-appropriate resistance exercise.
Muscle strength is also a key factor in facilitating motorto be associated with more physically active lifestyles during become competent in many motor skills may be more likely to we recommend that the BOKS exercise curriculum incorporates more motor skill training in an integrated and progressive manner. Research indicates that productive motor skill training can be systematically added to physical activity programs in a Although this research project assessed changes in selected physical parameters over a relatively brief 9-week training period, other studies have demonstrated that longer duration school-based exercise programs are effective for improving time in elementary aged youth. A 9-month school-based exercise program with 8 to 9 year old children in the United States showed school-based physical activity programs concluded that highsuggested that continued participation in the BOKS beforeschool exercise program may facilitate further improvements in the children's body composition and components of physical additional research of the BOKS before-school physical activity program is warranted. We recommend that future studies use a longer training period, with assessments taken near the beginning and end of the school year (e.g., September to June). We also suggest including assessments of leg pushing strength (e.g., leg press performance) and upper body pushing strength (e.g., chest press performance) to better evaluate strength changes in the major muscle groups that are more actively involved in the BOKS exercise program.

Conclusion
The results of this study indicate that the BOKS before-school physical activity program is effective for reducing percent body fat, decreasing fat weight, and increasing aerobic performance in preadolescent boys and girls.