1 SPORTS GAME PLAY: A COMPARISON OF MODERATE TO

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SPORTS GAME PLAY: A COMPARISON OF MODERATE TO VIGOROUS
PHYSICAL ACTIVITIES IN ADOLESCENTS
Patience, M.A., Department of Kinesiology and Sport Sciences, Coastal Carolina
University, Kilpatrick, M.W, Sun, H. Flory, S.B., Watterson, T.A. School of Physical
Education and Exercise Science, University of South Florida, Tampa, FL 33620
Marcia A. Patience (Corresponding Author):
Professor
Coastal Carolina University
Phone: (843) 349-2734
Fax: (843)
Email: [email protected]
Kilpatrick, M.W., PhD
Associate Professor
University of South Florida
4202 E. Fowler Ave.
Tampa, FL 33620
Phone: (813) 974-8127
Fax: (813) 974-4979
Email: [email protected]
Sun, H., PhD
Assistant Professor
University of South Florida
4202 E. Fowler Ave.
Tampa, FL 33620
Phone: (813) 974-0119
Fax: (813) 974-4979
Email: [email protected]
Flory, S.B., PhD
Assistant Professor
University of South Florida
4202 E. Fowler Ave.
Tampa, FL 33620
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Phone: (813) 974-4765
Fax: (813) 974-4979
Email: [email protected]
Watterson, T.A.
Professor
University of South Florida
4202 E. Fowler Ave.
Tampa, FL 33620
Phone: (813) 974-4765
Fax: (813) 974-4979
Email: [email protected]
Acknowledgements:
This work was privately funded by Bay Area Pelicans under the direction of Rugby 4
Life and More Health Inc. Special thanks to the participants and volunteers of the study
for dedicating time for the purpose of the project.
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ABSTRACT:
Physical activity (PA) in adolescents has been steadily declining. Research suggests
sports may improve PA in adolescents. Flag rugby may provide adolescents an
alternative to traditional team sports. Since adolescents are more likely to participate in
activities they enjoy, sports game play has become increasingly important in physical
education (PE) classes. PURPOSE: To compare adolescent PA intensity, duration,
competence and enjoyment in flag football (FF), basketball (BB), and flag rugby (FR).
METHODS: 101 (55 male; 46 female, age 11-14) students were selected to participate in
three week sport units of FF, BB, and FR. Activity counts were collected using the
Stayhealthy RT3™ accelerometer on the last day of each unit to determine activity
duration in minutes and average intensity with metabolic equivalent of task (MET).
Students’ perceived competence and enjoyment of each sport was measured by the
intrinsic motivation inventory (IMI). Data were analyzed by RMANOVA. RESULTS:
Mean MET values were: FF 4.9 + 1.4(SD), BB 5.5 + 2.0, and FR 6.0 + 1.5, with
significant differences noted for FF and BB (p < 0.001) and FR and FF (p < 0.001). FF
produced an average duration of activity of 39.3 + 4.8, BB 40.6 + 5.9 and FR 41.8 + 4.8
minutes of activity. There was a significant difference between FR and FF durations (p <
0.001). Participants felt significantly more competent in FR than FF (p < 0.001) and
more competent in FF than BB (p < 0.001). Participants enjoyed FR significantly more
than FF and BB (p < 0.001). DISCUSSION: FR activity was greater in intensity than FF
and BB. Results of this study suggest participants enjoy sports game play. Sports such as
FF, BB and FR produce moderate to vigorous PA that may be beneficial for adolescent
health.
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BACKGROUND:
Significant increases in obesity and overweight percentages of the nation’s
adolescence have consistently been an important topic of research. Regular PA may
provide health benefits that transcend throughout an individual’s lifetime.1 Sports
activities are a major component to secondary PE curriculum as they produce more PA
and appear to be enjoyable for the adolescent.
Children tend to be more active than adults, but as they transition into
adolescence, activity levels begin to steadily decline.1 Among adolescents ages 12 to 19,
16% are overweight and 31% are overweight or at risk of becoming overweight.2 Most
states (86%) require middle schools to provide PE.3 Physical education classes are a
primary source of PA for the adolescent.4 Research suggests students have become more
active in PE, with the inclusion of games, sports or dance, thus increasing PA duration
from an average of 15 minutes to 18 minutes per class time. 3
The National Association for Sport and Physical Education (NASPE) requires
daily PE in an accumulation of at least 150 minutes per week for elementary students and
225 minutes per week for middle school and high school students.5 Presently, it appears
that a decrease in PA has become accepted as part of the norm, while participation in
sedentary activities, such as computer and video game use have gained popularity.6
Observations in the PE classroom of random middle schools revealed that 18% of
students engage in moderate to vigorous PA and 53% of those observed appeared to be in
an inactive state. 7 While 60 minutes per day of activity is recommended, the adolescent
population does not appear to be meeting these requirements.
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Research has well documented and confirmed that PA may benefit adolescents by
increasing their aerobic fitness, bone mass, and by reducing their risk of obesity and
hypertension.8 Many studies have demonstrated the associated health benefits to those,
including the young, who participate in sports.3 Sports are often taught at an early age.
Ninety-eight percent of schools teach group or team activities.3 It is commonly found that
sports games promote psychomotor skills and healthy lives.9 Therefore, sports may have
the potential to increase activity intensity and duration in adolescents while promoting
healthy lifestyle behaviors.
Collectively, research suggests adolescents who enjoy an activity, may engage in
the activity for longer durations.10 Greater participation tends to occur in activities that
are deemed to be more interesting. There is a strong link between continued PA and
enjoyment in PE in adolescents.11 Many sport activities are found to be enjoyable in the
adolescent population.12 Therefore, it seems likely that sports play in PE will be most
enjoyed by the adolescent.
Perceptions of competence, autonomy and perceived success are directly related
to PA enjoyment and thus linked to self-efficacy and motivation behavior.13-14 It is
important that intrinsic motivation and self-efficacy be fostered as adolescents transition
into middle school, high school and throughout adulthood.
Middle school students appear to be physically active in PE an average of 40
minutes.3 Eight percent of middle schools provide daily PE for the entire school year and
15% offer daily PE for at least 18 weeks of the school year, suggesting the absence of
daily required PE class has contributed to the rise in overweightness and obesity.3 Past
research has revealed that adolescents age 9-15 spend more time in PA during the week
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than the weekend.4 Therefore, it is important that PA be maintained and/or improved in
PE in order for the adolescent to receive the benefits of daily PA.
One activity that has received relatively little attention in research is the sport of
flag rugby. For some PE programs, flag rugby is a relatively new activity and
participation is not equal to that of other sports such as soccer, baseball/softball, and
basketball. Even less is known about the youth version of flag rugby. Proponents of flag
rugby believe the fitness stimulus associated with participation is similar to traditional
American sports.15 The nature of the sport, flag rugby, requires movement of all players.
Therefore, the purpose of this study was to compare flag rugby with other popular team
sports such as, flag football and basketball, in adolescents. The youth flag rugby program
observed for this study was developed by Rugby 4 Life and implemented in this
particular PE class. Physical activity intensity and duration during game play were
measured. Perceptions of enjoyment and competence following performance were
measured in correlation with activity.
Review of Literature
Recently, there have been a number of published studies on interventions in PE.
These studies indicate that PE programs can potentially influence PA by making it more
enjoyable. A two-year middle school PE intervention, M-SPAN, observed 24 middle
schools and found lesson time that is allocated more efficiently can improve PA for
middle school students.16 In this intervention the instructors were also able to effectively
maximize activity by allowing additional game play time. In the Lifestyle Education for
Activity Program (LEAP), eighth grade females increased daily physical activity,
enjoyment of PA, enhanced PA self-efficacy and class participation during and after the
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program intervention.17 A study on the effects of a 2-year PE program on PA in
elementary school students found that allowing students to engage in game play increased
PA levels more than modifying the structure of the class.18
Sports based youth development programs have been studied to understand how
organized sport activities (tennis, soccer, basketball, baseball, etc.) contribute to learning
development of our youth.9 This research suggests that sports-based programs for our
youth tend to lead them toward positive social and behavioral development. Sports such
as basketball and soccer have the potential to promote cardiovascular fitness and typically
generalize to a child’s community.19 Sports provide youth additional benefits such as,
skill building, active learning and opportunities for recognition.9 The results from the
School Health Policies and Programs Study 2006 found that among the 78% of schools
that required physical education, most taught group or team activities.3
Some school systems follow a state or national standard for PE curriculum.1While
it appears necessary to have qualified PE instructors to teach skill, it does not seem to
significantly affect the amount of time adolescents spend in PA.1,20 It may be more
important that the PE instructors have sufficient class management skills, and
motivational skills. As adolescents become more motivated with improved skill, they
begin to play more vigorously and for longer durations.13-14 The following study provides
recent data detailing PA intensities and durations and the relationship to enjoyment and
perceived competence.
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METHODS:
Participants
One hundred and one (55 male, 46 female; age = 12.0 + 0.8 years) PE students
were recruited from a local middle school (grades 6-8) in the southeastern United States
to participate in this study. The students of this school are considered upper middle class
based on school demographics, specifically noted as only 20% of students received free
or reduced lunches. Students were primarily White/Caucasian (69%) or Latino (15%),
but also included: African-American (6%), Asian (4%) and Native American (<1%). The
participants consisted of sixth, seventh and eighth graders, with 349, 320, and 404
respectively. Students enrolled in this particular school have a period of 50 minutes
designated for PE class each day of the school week. School administration permission
was granted and student participants were solicited based on the permission of the PE
specialist who allowed access into each of her classes for the purposes of this research
study. Each participant signed an assent form as well as a signed informed consent form
from a parent or legal guardian. Written permission from the school, PE instructor and
administration were submitted and approved by the Institutional Review Board (IRB).
Instruments
The metabolic equivalent of task (MET) was used to determine intensity. The
ranges determined for moderate intensity were 3.0 to 5.9 MET and vigorous intensity was
6.0 MET or greater. Both were based on the guidelines for the adolescent
population.21All physiological-related variables were collected using the Stayhealthy
RT3™ accelerometer (Monrovia, USA). The Stayhealthy RT3™ accelerometer
(Monrovia, USA) is an electronic device that measures accelerations produced by body
movement. Accelerometers provide objective, nonreactive and reusable tools for
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assessing PA.22 Triaxial accelerometers perform equally well on children and adolescent
subjects.22 These devices are clipped to the waistband at the hip level or worn as a belt
and function to detect triaxial (forward, lateral, and vertical) movement. Accelerometers
are also known to detect various intermittent activity patterns, characteristically applying
to the adolescent.23 Additionally, these accelerometers are designed to detect both the
patterns of PA and total activity.22 Research suggests that three-dimensional
accelerometers provide better evaluations of free play activities in children than heart rate
monitors and uniaxial accelerometers.23 The accelerometer is preloaded with height,
weight, age and sex of the participant.
Interest-enjoyment and competence were measured using the two perceived
choice subscales of the Intrinsic Motivation Inventory (IMI), a multidimensional measure
of subjects’ experience with experimental tasks.24 This scale included four items
designed to assess interest-enjoyment of recently completed PA and four items that assess
the participant’s perceived competence in each activity. Scaling for the items uses a
seven-point Likert type scale that allows respondents to indicate agreement with
statements regarding enjoyment of the activity and perceived competence after
performing the activity.24 The 7-point likert-type scale included statements such as, “I
enjoyed doing this activity very much,”and “I think I am pretty good at this activity.” The
choices for the scale were, “not true at all, “somewhat true” and “very true.” The IMI
was chosen as a reliable tool for assessing individual perceptions of enjoyment and
competence during PA.24 Reliability of the measures used in this study were determined
by the coefficient alpha for interest-enjoyment at (0.84) and perceived competence at
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(0.80).24 Adolescents were asked to complete these forms directly after performing the
activity.
Procedure
Each participant involved in the study followed his/her daily routine for PE
class. The students were asked to participate in the sport unit they had most recently
completed. In each unit, one week was dedicated to learning the sport, one week was
dedicated to practicing skill, and the final week the students were allowed to engage in
free play. However, in the flag rugby unit, two days at the end of the unit included
additional coaching from the Rugby 4 Life professionals. Each class period involved a
brief dress out period and seated roll call. Accelerometers were distributed to
participating students during roll call. The student wore the accelerometer for the entire
class period and returned them to the researcher upon completion of the class period. The
students then completed the eight-item interest-enjoyment/competence questionnaires
printed on cardstock (thicker) paper. The accelerometers data were downloaded and
calibrated. Each student participated in each one of the sports on different occasions,
equaling three class periods. If a participant missed any of the three sports, the
participant was dropped from the study.
Data Analysis
The study design utilized a repeated measure analysis of variance (RMANOVA)
as the primary statistical test for this research. When all data were collected, Statistical
Package for the Social Sciences (SPSS) software was used to organize and analyze the
results of the study. Separate ANOVA’s were run for each dependent variable revealing
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significance among the three sports. Therefore, criterion for significance for all tests was
set at p < 0.01.
RESULTS:
Results from the IMI subscales for enjoyment and competence indicate excellent
reliability. Cronbach’s alpha reliability for internal consistency statistics scores for
enjoyment were as follows: flag football (0.94), basketball (0.95) and flag rugby (0.97).
Reliability scores for competency were as follows: flag football (0.9), basketball (0.93)
and flag rugby (0.94).
The results of this study indicate that there is a significant difference in intensity
during game play of flag rugby, flag football and basketball in adolescents. Flag football
mean MET values were 4.9 + 1.4 (Mean + SD), within the moderate intensity range.
Basketball mean MET values were 5.5 + 2.7 were in the upper moderate intensity range.
Flag rugby mean MET values were 6.0 + 1.5, reaching vigorous intensity ranges. These
results indicate no significant difference between flag football and basketball (p = 0.023).
Significant differences were found between flag rugby and flag football (p < 0.001).
There were no significant differences found between basketball and flag rugby (p =
0.109) (see Figure 1).
In this study, flag football produced an average duration of activity of 39.3 + 4.8,
basketball 40.6 + 5.9 minutes and flag rugby 41.8 + 4.8 minutes of activity (see figure 2
below). There was no significant difference between duration of flag football and
basketball activity (p = 0.080). There was no significant difference between basketball
and flag rugby (p = 0.098). However, there was a significant difference between flag
rugby and flag football durations (p < 0.001). (See figure 2)
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Statistical analysis results suggests participants enjoyed playing flag rugby (6.2 +
1.6) significantly more than flag football (5.4 + 1.7), at (p < 0.001). Flag rugby was also
found to be more enjoyable than basketball (5.2 + 1.8) at (p < 0.001). However, there
was no significant difference between enjoyment of basketball and flag football (p =
0.481). (See figure 3)
Participants felt significantly more competent playing flag rugby (6.0 + 1.5) than
flag football (5.3 + 1.6) (p < 0.001) (see Figure 4 below). There was also a significant
difference in competence between flag football and basketball (5.2 + 1.7) (p < 0.001).
However there was no significant difference between flag rugby and basketball (p =
0.827) competence. (See figure 4)
DISCUSSION:
The rates of childhood overweightness and obesity have become a topic of
concern for the nation. The reduction of PA in PE at the middle school level has
contributed to the overall decline in PA in adolescents.1 There is an immediate need to
find a solution to increase physical activity (PA) in adolescents. The purpose of this
research study was to understand the effect of sports games on adolescent PE
participation, specifically as it relates to enjoyment and competency. Understanding
exercise behavior in the adolescent population is necessary for increasing exercise
adherence.14 Past research has indicated that organized sports taught in PE can improve
adolescent fitness.12 Research suggests that enjoyment is related to adherence.14 Sports is
found to be interesting for the adolescent population and well documented in research.9
PE classes appear to be more popular when adolescents are taught various sports
activities that maintain their interest.1 Some sports activities taught at an early age,
13
contribute to improved skill development over time. Other sports are simply easy to
learn, such as flag rugby. While skill development can be improved, flag rugby is a sport
all ages can learn.13 Therefore, sports may be a partial solution for improving adolescent
PA.
This research study measured mean MET values, duration, competence and
enjoyment in sports game play in 101 students participating in PE. The significant
differences found among the sports demonstrated that flag rugby is on average more
enjoyable than basketball and flag football. Flag rugby produces more vigorous PA and
longer duration of activity, and participants also feel more competent in the game. Each
sport appeared to produce results that were beyond the expectations of the typical PE
class, assuring CDC requirements that attaining 40 minutes of activity is possible, given
the appropriate choice of activity.3 The current sample used in this study, followed
curriculum required by the county school district. The school district requires instructors
to teach individual and team sports during the two semesters of each year. This allows
the student more variability in finding a sport that fulfills individual enjoyment and
competence.
Limitations
It is thought the students may have felt more competent in the rugby game
because it was easy to learn. During collection of the final day of the flag rugby unit,
many students vocalized enjoyment toward this sport. Because flag rugby is an
alternative sport played in this middle school, it is presumed that the student may find it
more interesting compared to regular curricula related sports choices.
14
A possible strength of the study was the allowance for participation of all students
from consecutive class periods during the entire school day. Data were collected from
the same participants in each sport attending one instructor’s class. This limited
confusion, saved time and provided accurate body composition and demographic
information. Utilizing the same participants and instructor resulted in smooth
transitioning time between classes. This is important to note for future studies. Piloting
was important in this study. Errors and glitches were expected and handled appropriately
and timely due to the additional experience.
The accelerometer data were accurately recorded, as students could not control for
activity collection. For future studies the accelerometer is found to be a reliable
instrument for adolescent activity measurement. The activity counts were averaged
beginning with the first minute of use and ending on the last full minute of activity. It is
important for future studies that activity is based on average participant duration.
Conclusions
The results of this study indicate that adolescents enjoy playing sports such as,
flag football, basketball and flag rugby. In comparison to the other sports, flag football
was not found to be enjoyed as much, though participants were still at moderate
intensities for an average of 39 minutes. This study concludes that adolescents
participating in each of the three sports maintained MVPA that met duration
recommendations of the NASPE.5
IMPLICATIONS FOR SCHOOL HEALTH
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This study contributes to research as it details the behaviors of adolescent PA
patterns in PE classes. As a suggestion for future studies, it would be important to
measure and analyze other sports. The difference between middle school male and
female activity based on sport enjoyment may be an important variable for future studies.
The purpose of this research was to measure activity in popular organized sports.
Activity intensity, duration, enjoyment and competence were all important variables that
contribute to understanding the patterns of PA in adolescents. Research has welldocumented the benefits of PA in adolescents as well as the relationship between
enjoyment and the continuation of activity.11 Sports games are found to be interesting to
adolescents.12 Therefore, it is important the adolescent be taught sports in PE.
Figure 1
Mean MET Performance and Standard Error Values
MET
Note. (*) indicates a significant difference between flag rugby and flag football with a pvalue less than 0.001.
Figure 2
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Mean Activity Duration and Standard Error Values
Duration
Note. (*) indicates a significant difference between flag rugby and flag football with a pvalue less than 0.001
Figure 3
Mean Enjoyment and Standard Error Values
Enjoyment
Note. (*) indicates a significant difference between flag rugby and basketball and flag
rugby and flag football with a p-value less than 0.001
Figure 4
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Mean Competence and Standard Error Values
Competence
Note. (*) indicates a significant difference between flag football and basketball and flag
rugby and flag football with a p-value less than 0.001
REFERENCES:
1. Pate, R.R., Davis, M.G., Robinson, T.N., Stone, E.J., McKenzie, T.L. & Young,
J.C. Promoting physical activity in children and youth: A leadership role for
schools: A scientific statement from the American Heart Association Council on
nutrition, physical activity, and metabolism (Physical Activity Committee) in
collaboration with the councils on cardiovascular disease in the young and
cardiovascular nursing. Journal of the American Heart Association. 2006;114
1214-1224.
2. Hedley, A.A., Ogden, C.L., Johnson, C.L., Carroll, M.D., Curtin, L.R., Flegal,
K.M. Prevalence of overweight and obesity among US children, adolescents and
adults, 1999-2002. Journal of the American Medical Association. 2004;
291(23)847-2850.
3. Lee, S.M., Burgeson, C.R., Fulton, J.E. & Spain, C.G. Physical education and
physical activity: Results from the school health policies and programs study
2006. J Sch Health. 2007;77(), 435-463.
4. Nader, P.R., Bradley, R.H., Houts, R.M., MacRitchie, S.L., O’Brien, M.O.
Moderate-to vigorous physical activity from ages 9-15 years. American Medical
Association. 2008; 300(): 295-305.
18
5. National Association for Sport and Physical Education. Physical activity for
children: A statement of guidelines for children ages 5-12. Reston, VA: Author.
2004.
6. Corbin, C.B., & Pangrazi, R.P. Physical activity for children: A statement of
guidelines for children ages 5-12. Reston, VA: National Association for Sports
and Physical Education. 2004.
7. Mhurchu, C.N., Maddison, R., Jiang, Y., Jull, A., Prapaessis, H., Rogers, A.
Couch potatoes to jumping beans: A pilot study of the effect of active video
games on physical activity in children. Intl J Behav Nutr Physical Act. 2008;
5(8): 1-5.
8. Bocarro, J.N., Kanters, M.A., Cerin, E., Floyd, M.F., Casper, J.M., Suau, L.J.,
McKenzie, T.L. School sport policy and school-based physical activity
environments and their association with observed physical activity in middle
school children. Health & Place. 2011;08 (): 007.
9. Perkins, D.F. & Noam, G.G. Characteristics of sports-based youth development
program. New Directions for Youth Development. 2007;115(10): 75-106.
10. Garton, A.F., & Pratt, C. Leisure activities of adolescent school students:
predictors of participation and interest. J Adolescence. 1991; 14: 305-321.
11. Cairney, J., Kwann, Y.W., Velduizen, S., Hay, J., Bray, S.R., & Faught. Gender,
perceived competence and the enjoyment of physical education in children: a
longitudinal examination. Intl Behav Nutr Phys Act. 2012; 9(26): 1-8.
12. Hoffman, J.R., Kang, J., Faigenbaum, A.D., & Ratamess, N.A. Recreational
sports participation is associated with enhanced physical fitness in children. Res
Sports Med. 2005; 13(2): 149-161.
13. Ferrer-Caja, E., & Weiss, M.R. Predictors of intrinsic motivation among
adolescent students in physical education. Res Q for Exerc Sport. 2000; 71(3):
267-279.
14. Ryan, R.M. Control and information in the intrapersonal sphere: An extension of
cognitive evaluation theory. Journal of Personality and Social Psychology. 1982;
3:450-461.
15. Mathesius, P. & Strand, B. Touch rugby: An alternative activity in physical
education. JOPERD. 1994; 65: 55.
16. McKenzie, T.L., Sallis, J.F., Prochaska, J.J., Conway, T.L., Marshall, S.J. &
Rosengard, P. Evaluation of a two-year middle-school physical education
intervention: M-SPAN. Med Sci Sports Exerc. 2004; 04: 1382-1388.
19
17. Pate, R.R., Ward, D.S., Saunders, R.P., Felton, G., Dishman, R.K., Dowda, M.
Promotion of physical activity among high-school girls: A randomized controlled
trial. Am J Public Health. 2005; 95(9):1582-1587.
18. Sallis, J.F., Mackenzie, T.L., Alcaraz, J.E., Kolody, B., Faucette, N., & Hovell,
M.F. The effects of a 2-year physical education program (SPARK) on physical
activity and fitness in elementary school students. Am J Public Health. 1997; 87
(8): 1328-1334.
19. Simons-Morton B.G., Taylor W.C. Snider S.A., Huang, I.W., & Fulton, J.E.
Observed levels of elementary and middle school children's physical activity
during physical education classes. Prev Med. 1994; 23: 437-441.
20. McKenzie, T.L., Nader, P.R., Strikmiller, K., Yang, M., Stone, E.J., Perry, C.L.,
Taylor, W.C., Epping, J.N., Feldman, H.A., Luepker, R.V., & Kelder, S.H. School
physical education: Effect of the child and adolescent trial for cardiovascular
health. Prev Med. 1996; 25: 423-431.
21. Haskell, W.L., Lee, I., Pate, R.R., Powell, K.E., Blair, S.N., Franklin, B.A.,
Macera, C.A., Heath, G.W., Thompson, P.D., & Bauman, A. Physical activity
and public health: Updated recommendation for adults from the American
College of Sports Medicine and the American Heart Association. Circulation.
2007; 116:000-000.
22. Sirard, J.R. & Pate, R.R. Physical activity assessment in children and adolescents.
Sports Med. 2001; 31(6): 439-454.
23. Trost, S.G. Objective measurement of physical activity in youth: Current issues,
future directions. Exercise and Sport Sciences Reviews. 2001; 29: 32-36.
24. McAuley, E., Duncan, T. & Tammen, V.V. Psychometric properties of the
intrinsic motivation inventory in a competitive sport setting: A confirmatory
factor analysis. Res Q for Exer Sport. 1989; 60: 48-58.
25.
Motl, R.W. Dishman, R.K., Saunders, R., Dowda, M., Felton,G., Pate, R.R. (2001).
Measuring Enjoyment of Physical Activity in Adolescent Girls. American Journal
of Preventive Medicine, 21, (2), 110-117