Magazine 2013
International Peer-Reviewed Journal  
RH, VOL. 3 JULY 2013  
Green ClothPhysical Activity And Fitness In Children  
Rita Patil and S.A.Udipi  
The importance of physical activity is known in the treatment and prevention of various lifestyle disorders.  
Physical activity helps maintain good health. The benefits of physical activity vary from improved  
physical fitness, low risk of obesity and other lifestyle disorders like diabetes mellitus, metabolic  
syndrome and cardiovascular disease. The intensity, frequency and duration of physical activity are  
important aspects as they are also protective against diseases such as osteoporosis, depression, and  
anxiety, extending to adults and children. All countries in the world, rich and poor facing the problem of  
reduced physical activity and higher incidence of obesity. This review highlights the importance of  
physical activity and fitness as well as the factors affecting them. The effects of low activity in children  
and also parental encouragement of exercise, level of education, participation in organized sports after  
school years and contribution to changes in physical activity patterns are highlighted. Recommendations  
for physical activity are suggested. The changes in the type and amount of free play in children are  
identified. Therefore special efforts have to be taken to increase physical activity in children. Parents  
play a big role in helping kids to remain active. Active behaviours of parents are copied by children.  
Thus they can and should encourage children to participate in active sports in school and active play in  
leisure time. There is also a need for parents to limit a child’s daily TV and computer time.  
Keywords - Physical Activity, Obesity, Disease, Children, Parents.  
Physical activity is defined as any physical movement produced by skeletal muscles that result in energy  
expenditure whereas; exercise is planned, structured, systematic and purposeful activity (Haskell and Kiernan,  
000). Physical activity is important in the treatment and prevention of various physical and psychological  
disorders (Peluso and Andrade, 2005) and has an important role in all round development of children Byrne and  
Hills, 2007).  
Physical activity and fitness is affected by gender and socio-cultural factors in childhood and adolescence.  
Children appear to become less active as they get older, and show decreases in activity levels during adolescence.  
Fitness parameters change before puberty (Keller, 2008).  
The term ‘physical activity’ is often used alternately with ‘physical exercise’ and ‘physical fitness’, however  
each of them have specific meanings. Fitness involves daily physical activity or exercise (Ortega, 2008). Physical  
fitness is the ability to perform daily tasks with ease or without fatigue. It is an integrated function involving  
skeletal, muscular, cardio respiratory, neurological, endocrine and other body systems (Deforche et al., 2003).  
Physical activity is known to have a positive role in maintaining health. It is reported that regular physical  
activity leads to improved physical fitness, reduced risk of obesity and metabolic problems (diabetes mellitus,  
metabolic syndrome, heart disease). Regular involvement in physical activity is protective against diseases  
such as coronary heart disease, hypertension, noninsulin-dependent diabetes mellitus, osteoporosis, depression,  
and anxiety in children (Simons- Morton et al., 1997; Powell et al., 2006; Parfitt et al., 2009). Countries with  
lower incomes and lower education levels are equally facing the problem of increased incidence of obesity like  
the developed or affluent countries (Kelishadi et al., 2007). It is therefore important to study physical activity  
and fitness, and the factors affecting them.  
Activities of daily life, such as standing, walking slowly, lifting lightweight objects and climbing stairs are  
called baseline activities. They are of light intensity. Those who do only baseline activity are called inactive. The  
additional activity like brisk walking, jumping rope, and dancing, lifting weights, climbing on playground  
equipment and doing yoga is called health enhancing activity. Each of these activities has its own health  
benefits. Aerobic activities are running, hopping, skipping, jumping rope, swimming, dancing, and bicycling.  
These activities increase cardio respiratory fitness. Muscle-strengthening activities over loads muscles while  
doing work and strengthens the muscles. Playing on playground equipment, climbing trees, and playing tug-  
of-war are examples of this type of activity. Bone-strengthening activities promote bone growth and strength.  
Running, jumping rope, basketball, tennis, and hopscotch are bone strengthening activities (Shetty, 1997).  
International Peer-Reviewed Journal  
RH, VOL. 3 JULY 2013  
Types of Physical Activity  
Inactivity is when there is no activity beyond baseline activities of daily living.  
Low activity is activity more than baseline but less than 2 hours 30 minutes of moderate physical activity a week  
or 75 minutes-1 hour 15 minutes of vigorous activity.  
Medium activity is 150 minutes to 300 minutes of moderate activity a week or 75 to 150 minutes of vigorous  
physical activity per week.  
High activity is more than 300 minutes of moderate physical activity every week.  
(, 2008).  
The intensity, frequency and duration of physical activity are important. Intensity indicates how hard a person  
works to do the activity. Moderate intensity is a term used for brisk walking. Vigorous intensity is when a person  
is running/jogging. Frequency is how often a person does aerobic activity and duration is for how long a  
activity session is.  
The benefits of regular physical activity are-  
Increases lean muscle and decreases body fat.  
Helps maintain weight.  
Increases bone strength.  
Helps to reduce depression, anxiety and improves mood.  
Lowers the risk of obesity and other lifestyle disorders.  
Relieves tension and stress.  
Decreases mortality.  
Naidu and Sakalkale, 2011).  
Overall Mortality  
Higher levels of regular physical activity are associated with lower mortality rates among adults. Even  
moderate activity on a regular basis results in lower mortality rates as compared with those who are least active.  
Physical inactivity ranks fourth on the WHO list of causes of death (WHO, 2009).  
Cardio-vascular Diseases  
Hypertension causes strokes, coronary artery disease and congestive heart failure in adults. Regular  
physical activity can lower both systolic and diastolic blood pressure in adults with hypertension. It appears  
that regular physical activity can also lower blood pressure in children and adolescents. Physical inactivity and  
poor levels of physical fitness are associated with obesity and coronary heart disease risk factors in children.  
Aerobic activity burns calories, reduces weight, decreases the risks of heart disease and high blood pressure.  
It also helps to gain stamina and endurance (Byrne and Hills, 2007). Running, skating, cycling, walking, hiking  
and jumping rope are examples of aerobic activities (Shetty, 1999). Several studies have reported cardio-  
vascular fitness to be better in children who were physically active (Hussey et al., 2001; Gutin et al., 2005;  
Stratton, 2007; Burgi et al., 2011). Children should do activities at a brisk and comfortable pace for at least 20  
minutes three times per week. Exercises for gaining muscle strength and endurance should be three times a  
week after cardiovascular activity as this is also important for children (Brambilla et al., 2011).  
Maintains Skeletal Health and Body Composition  
Physical activity is necessary for normal skeletal development and is also associated with body fat  
levels. Development of bones is at the peak during the pubertal year. Physical activity helps build greater bone  
density in childhood as well as maintain peak bone density in adulthood. Regular physical activity regimens  
are advised for children and adolescents to maintain and improve bone development (Pitukcheewanont et al.,  
Youth who are relatively high in physical activity tend to have lower skin folds and total body fat. Physical  
activity is significantly correlated with body fat by several researchers (Mikkelsson et al., 2006; Ruiz et al., 2006;  
Rowland et al., 2006). Fitness is significantly affected by body fat. Lean body mass and physical activity  
contributes to good fitness (Ortega et al., 2010; Dencker et al., 2011).  
International Peer-Reviewed Journal  
Social and Mental Development  
RH, VOL. 3 JULY 2013  
Regular physical activity promotes psychological health in children- it improves self-esteem, reduces  
anxiety level and stress. It relieves the symptoms of depression and is a mood enhancer. Psychological well-  
being has been associated with vigorous and structured aerobic activity in adolescents and children (Crews et  
al., 2004; Stella et al., 2005).  
Prevents Obesity and Life Style Disorders  
The associations between obesity, cardio vascular disease and type II diabetes are well established  
today in adults and even in children. Sedentary lifestyle increases the risk of obesity. Reducing sedentary  
behaviors like watching television and playing computer games, is important for preventing obesity (Denney-  
Wilson and Baur, 2007; Brambilla et al., 2011; Michalopoulou et al., 2011).  
Physical activity is beneficial for better fitness and preventing obesity (Elnashar and Mayhew, 1984;  
Jopling, 1988). Physically active adults had significantly better childhood physical fitness test scores than the  
inactive adults. The risk of physical inactivity in young adulthood was significantly related to the low scores in  
the run and sit-ups tests as children. Parental encouragement of exercise, level of education, participation in  
organized sports after school years and spousal encouragement of exercise contributed significantly to the  
physical activity. Therefore physical fitness testing in childhood can help identify those at increased risk of  
becoming physically inactive young adults (Dennison et al., 1988).  
Sallis et al., (1997) reported that physical activity was significantly associated with fitnesscomponents.  
Active childrenappeared to participate in various activities which were beneficial to health-related fitness. Similar  
observations were made by other researchers (Prista et al., 2003; Tremblay et al., 2005; Christodoulos and  
Flouris, (2006; Trudeau et al., 2009; Zarrouk et al., 2009; Burgi et al., 2011).  
Chen et al., (2008) assessed physical fitness and activity in 331 children, aged 7 – 8 years in Taiwan. The  
study reported the effect of socio economic status factors and physical activity on fitness. Older children had  
significantly better flexibility than younger children. Urban school boys had poor flexibility than rural school  
boys. Urban girls also had better flexibility and higher scores than rural girls.  
Sedentarism is defined as purposeful and extended engagement in behaviours characterized by minimal  
movement, low energy expenditure and rest (Tremblay, 2010). Sedentarism/physical inactivity is closely linked  
to skeletal health, cardiovascular disease risk, fitness and psychological factors. This change is due to rapid  
economic growth, modernization, urbanization, globalization of food markets. (Hills, 2009).  
Causes of Inactivity  
Increased TV viewing time.  
Reduced physical education in schools.  
Lesser time for free play before, during, and after school.  
Lack of facilities like grounds, gyms, parks, stadiums.  
Increased use of transport rather than walking.  
Use of equipment, labor saving appliances such as washing machines.  
Lesser physical activity in the workplace due to computers.  
Use of remote controls and computers for entertainment and leisure activities.  
Use of elevators and escalators.  
Reduced outdoor play because of cyber gaming, Internet and chat programmes.  
(Shetty, 1999).  
TV viewing and fitness of children  
Television viewing and playing video games and even a poor participation in sports is a cause of obesity,  
as against physical activity which is protective. The link between television viewing and children’s risk of overweight  
has been studied and a close association between physical activity and increased levels of obesity among  
International Peer-Reviewed Journal  
RH, VOL. 3 JULY 2013  
children has been reported by Gortmaker et al., (1996); Hanley et al., (2000); Shingo and Takao, (2002); Gray  
and Smith, (2003); Jago et al., (2005); Wiecha et al., (2006); Fairclough et al., (2009) and Mota et al; (2010).  
Role of family in fitness  
An active lifestyle is learnt from the family in early life. Involving children in activities gives them a positive  
role model and they can also remain motivated to be active in later life too. The habit of daily physical activity  
can be a good alternative to sports. Families have reported that neighbourhood safety and availability of  
recreational facilities influence physical activity in children (Floriani, (2007); Telford et al., (2008); Conwell et al.,  
Role of school in fitness  
Schools play an important role in maintaining good physical activity and health. Educational programs  
in school can help children to exercise which will be good for their health in later life too. Sallis et al., (1997)  
evaluated physical education to increase physical activity in and out of school. They reported that children  
were physically active for more time when they were led by experts/ teachers than the control. Manios et al.,  
1998) reported that children performed significantly better in various fitness tests after three years of health  
intervention programme. Simsilar observations were reported by Koutedakis and Bouziotas, (2003); Zahner et  
al., (2006); Hesketh et al., (2008) and Lundgren et al., (2010).  
Legarde and LeBlanc (2010) reviewed the school environment for physical activity. They suggested that  
schools are an ideal surrounding as they can provide a variety of activities to improve physical activity levels in  
children. They also suggested interventions which included safe physical education and physical activity,  
extracurricular physical activity and active transport to school.  
Promotion of active commuting to school can be an important way to increase levels of physical activity  
in school children. This was suggested by Panter et al (2011) after studying the associations between active  
commuting, levels of physical activity and distance to school in 9–10 year old children. For both boys and  
girls, significant positive associations were observed between walking to school and physical activity as well as  
in moderate to vigorous physical activity during weekday travel to school. The association was also better  
when the distance of the school was longer.  
Environmental Factors Influencing Physical Activity  
The environmental factors affecting physical activity include availability of activity promoting facilities  
(grounds, gyms, parks, stadiums, drive in facilities, elevators and escalators); automation and computerization;  
efficient and sedentary transport; cyber gaming, Internet and remote controls (Dietz, 1996; Wen et al; 2003).  
Urbanisation and increased mechanisation have led to a decrease in physical activity. It has caused a change  
in occupations, life-styles, dietary practices and family structures, (Shetty, 1999). Lack of proper streets and  
sidewalks is associated with lowered physical activity and increased risk of obesity. Leisure time has increased  
but is spent in television viewing, internet and cyber games resulting in reduced sleeping time (Lopez and  
Hynes, 2006).  
Other Factors Affecting Physical Activity  
Physical activity patterns can vary with ethnicity, gender, age, season and BMI. Rural schools reported  
availability of more play area compared to urban schools. However, urban children had accessibility to exercise  
equipment at home (Loucaides et al, 2004). Duncan et al., (2008) have reported boys to be significantly more  
active than girls.  
It is important that children are physically active throughout the week. The American Academy of Pediatrics  
recommended in 2006 that children and adolescents should have 60 minutes of physical activity daily. The  
United States Department of Health and Human Services also recommended that vigorous physical activity  
should be included at least once a week and strength training exercises should be included three days per  
week (ADA, 2008). People who participate regularly in physical activity for a longer duration or of high intensity  
may receive better health benefits. At the age of five years a child having regular 10 minutes of moderate to  
vigorous activity will have 0.2 kg less body fat at 8 years (Janz et al., 2009).  
Organized sports are one strategy to have a daily physical activity pattern. Physical activity can be of  
varying frequency, duration and intensity depending on the sport it is associated with. Children between 6–14  
International Peer-Reviewed Journal  
RH, VOL. 3 JULY 2013  
years who are involved in sport tend to be more physically active (Wickel and Eisenmann, 2007; Katzmarzyk  
and Malina, 1998).  
The type and amount of free play in children has changed (Burdette and Whitaker, 2005). Therefore  
special efforts have to be taken to increase physical activity in children. Parents play a big role in helping kids  
to remain active. Active behaviours of parents are copied by children. They can and should encourage children  
to participate in active sports in school and active play in leisure time. Parents should also limit a child’s daily  
TV and computer time (Yeung et al; 2007).  
Most of the physicalactivity in preschoolers is motor play and therefore the term play should be used to  
maintain or increase physical activity in small children. Play aids social,emotional and cognitive development  
of children. Regular physical activity in childhood will help children to develop healthy and fitness friendly  
behaviors throughout life. Family, health professionals, schools and communities all need to get together and  
make an effort to increase the physical activity levels of children. (Burdette and Whitaker, 2005). Thus it will be  
useful if physical activity is promoted byencouraging play.  
Moderate physical activity for children can be in the form of walking fast, bicycling, jumping, dancing  
and playing active games like football, cricket, basketball etc. Walking does not require special facilities. It can  
be encouraged for all age groups; males, females as well as for any income group (MacAuley, 1999).  
The physical activity pyramid shows the different types of activities and recommendation for them. Physical  
Activity Pyramid-  
Do Less  
Play Computer  
games, Watch  
TV, Use labor  
saving devices.  
Recreational Activities  
-3 days/week  
Football, Basketball, Hiking,  
Skating, Dancing, Yoga,  
Martial Arts  
Aerobic Exercise Flexibility Exercise  
2-3 days/week  
8-10 Exercises  
-5 days/week  
-3 days/week  
0-60 minutes  
Running, Cycling,  
Stair stepping  
Physical Activity  
Most Days of the week  
Accumulate more than  
Take the Stairs  
Walk, clean your house.  
0 minutes  
(, 1999)  
The fast moving lifestyle and the constantly increasing variety of entertainment available is moving children from  
active play to being sedentary. Physical activity can be promoted by doing the following-  
Increasing the awareness of physical fitness and the importance of physical activity.  
Encouraging physical activity at home and schools.  
Providing facilities for physical activity.  
International Peer-Reviewed Journal  
RH, VOL. 3 JULY 2013  
ADA. (2008). Position of the American Dietetic Association: Nutrition guidance for healthy children ages 2-11  
years. JADA. 108(6): 1038-1047.  
Find all citations by this author (default).  
Brambilla, P; Pozzobon, G ; Pietrobelli, A. (2011). Physical activity as the main therapeutic tool for metabolic  
syndrome in childhood. International Journal of Obesity 35, 16-28.  
Burdette, H.L; Whitaker, R.C. (2005). Resurrecting Free Play in Young Children Looking Beyond Fitness and  
Fatness to Attention, Affiliation, and Affect. Arch Pediatr Adolesc Med. 159:46-50.  
Burgi, F; Meyer, U; et al. (2011). Relationship of physical activity with motor skills, aerobic fitness and body fat  
in preschool children: a cross-sectional and longitudinal study (Ballabeina). International Journal of Obesity,  
Christodoulos, A.D; Flouris, A.D; Tokmakidis, S.P. (2006). Obesity and physical fitness of pre-adolescent children  
during the academic year and the summer period: effects of organized physical activity, Journal of Child Health  
Care, Vol. 10, No.3, 199 – 212.  
Conwell, L.S; Trost, S.G; Spence, L. et al. (2010). The feasibility of a home-based moderate-intensity physical  
activity intervention in obese children and adolescents. British Journal of Sports Medicine 44(4):250-5.  
Deforche, B; Lefevre, Johan; Bourdeaudhuij, I.D. et al (2003). Physical Fitness and Physical Activity in Obese  
and Nonobese Flemish Youth. Obesity Research 11:434-441.  
Dencker, M; Hermansen, B; Bugge, A. et al. (2011). Predictors of VO2Peak in children age 6- to 7-years-old.  
Pediatr Exerc Sci;23(1):87-96.  
Dennison, B.A; Straus,J.H; Mellits, E.D and Charney, E. ( 1988). Childhood Physical Fitness Tests: Predictor of  
Adult Physical Activity Levels? Pediatrics. 82 (3): 324 -330.  
Duncan, M.J; Woodfield, L; Al-Nakeeb, Y; Nevill, A.M. (2008). Differences in physical activity levels between  
white and South Asian children in the United Kingdom. Pediatr Exerc Sci; 20(3):285-91.  
Elnashar, M.A. and Mayhew, J. L. (1984). Physical Fitness status of Egyptian children aged 9-18 years. Br J  
Sports Med. 18 (1): 26-29.  
Fairclough, S.J; Boddy,L.M; Hackett A.F; Stratton, G.(2009). Associations between children’s socioeconomic  
status, weight status, and sex, with screen-based sedentary behaviours and sport participation. Int J Pediatr  
Obes. 4(4):299-305.  
Gortmaker, S.L; Must, A; Sobol, A.M. (1996). Television Viewing as a Cause of Increasing Obesity Among  
Children in the United States, 1986-1990. Arch Pediatr Adolesc Med. 150(4):356-362.  
Gray, A and Smith, B.S. (2003). Fitness dietary intake and body mass index in urban Native American Youth. J  
Am Diet Assoc. 103: 1187-1191.  
Gutin, B; Yin, Z; Humphries, M.C; Barbeau P. (2005). Relations of moderate and vigorous physical activity to  
fitness and fatness in adolescents. Am J Clin Nutr. 81(4):746-50.  
Hanley, A.J; Harris, S.B; Gittelsohn .J. (2000). Overweight among children and adolescents in a Native Canadian  
community: prevalence and associated factors. Am J Clin Nutr. 71(3):693-700.  
Haskell, W.L and Kiernan, M. (2000). Methodologic issues in measuring physical activity and physical fitness  
when evaluating the role of dietary supplements for physically active people. Am J Clin Nutr. 72 (2): 541S-550S.  
Hesketh, K; Graham, M and Waters. E. (2008). Children’s After-School Activity: Associations with Weight Status  
and Family Circumstance. Pediatric Exercise Science; 20(1): 84-94.  
International Peer-Reviewed Journal  
RH, VOL. 3 JULY 2013  
Hills, A.P. (2009). It’s time to be more serious about activating youngsters: lessons for childhood obesity. J  
Exerc Sci Fit. 7(2)Suppl: S28-S33  
Hussey,J; Gormley, J and Bell, C.(2001). Physical activity in Dublin children aged 7–9 years. Br J Sports Med.  
35(4): 268–272.  
Jago, R; Baranowski, T; Baranowski, J.C. (2005). BMI from 3-6 y of age is predicted by TV viewing and  
physical activity, not diet. Int J Obes. 29(6):557-64.  
Janz, K.F; Kwon, S; Letuchy, E.M. (2009). Sustained effect of early physical activity on body fat mass in older  
children. Am J Prev Med. 37(1):35-40.  
Katzmarzyk, P.T; Find all citations by this author (default).  
Kelishadi, R; Ardalan, G; Gheiratmand, G. (2007). Association of physical activity and dietary behaviours in  
relation to the body mass index in a national sample of Iranian children and adolescents: CASPIAN Study.  
Bulletin of the World Health Organisation; 85: 19-26.  
Keller, B.A. (2008). Development of Fitness in Children: The Influence of Gender and Physical Activity. American  
Journal of Lifestyle; 2: (1), 58-74.  
Koutedakis, Y. and Bouziotas, C. (2003). National physical education curriculum: motor and cardiovascular  
health related fitness in Greek adolescents. Br J Sports Med. 37:311-314.  
Lagarde, F. and LeBlanc, C. (1010). Policy options to support physical activity in schools. Can J Public Health.  
101(Suppl 2): S9-13.  
Long, D.E; Gaetke, L.M; Perry, S.D. (2010). The assessment of physical activity and nutrition in home schooled  
versus public schooled children. Pediatr Exerc Sci. 22(1):44-59.  
Lundgren, S.S; Daly R. M; Karlsson, M.K. (2010). A School Based exercise intervention program increases  
muscle strength in prepubertal Boys. International Journal of Pediatrics. Vol. 2010  
Maddison, R; Foley, L; Ni, M. (2011). Effects of active video games on body composition: a randomized  
controlled trial. Am J Clin Nutr. 94(1):156-63.  
Malina, R. M. (2009). Children and Adolescents in the Sport Culture: The Overwhelming Majority to the Select  
Few. J Exerc Sci Fit; Vol 7 (2), S1–S10.  
Mikkelsson, L O; Nupponen, H; Kaprio, J. (2006). Adolescent flexibility, endurance strength, and physical  
activity as predictors of adult tension neck, low back pain, and knee injury: a 25 year follow up study. Br J  
Sports Med; 40:107-113.  
Mota J, Ribeiro JC, Carvalho J, Santos MP, Martins J. (2010). Television viewing and changes in body mass  
index and cardio respiratory fitness over a two-year period in schoolchildren. Pediatr Exerc Sci. 22(2):245-53.  
Naidu, S.L. and Sakalkale, A.H. (2011). Comparative study of physical and physiological parameters of active  
and sedentary women. In Proceedings of the National Congress on Physical Activity and Health. Dept.of Physical  
Education, University of Pune.  
Ortega, F.B; Ruiz, J.R; Hurtig-Wennlöf, A. (2010). Cardiovascular fitness modifies the associations between  
physical activity and abdominal adiposity in children and adolescents: the European Youth Heart Study. Br J  
Sports Med; 44(4):256-62.  
Panter, J; Jones, A; Van, S.E; Griffin S. (2011).The influence of distance to school on the associations between  
active commuting and physical activity. Pediatr Exerc Sci. 23(1):72-86.  
Parfitt G, Pavey T, Rowlands AV. (2009). Children’s physical activity and psychological health: the relevance of  
intensity. Acta Paediatr. 98(6):1037-43.  
Peluso, M and Andrade, L. (2005). Physical activity and mental health: the association between exercise and  
mood. Clinics. 60 (1).  
International Peer-Reviewed Journal  
RH, VOL. 3 JULY 2013  
Pitukcheewanont P, Punyasavatsut N and Feuille M. (2010). Physical activity and bone health in children and  
adolescents. Pediatr Endocrinol Rev. 7(3):275-82.  
Prista, A; Antonio, J; Maia, R. et al (2003). Anthropometric indicators of nutritional status: implications for  
fitness, activity and health in school-age children and adolescents from Maputo, Mozambique. Am. J. Clin.  
Nutr. 77(4): 952-959.  
Rowlands, A.V., Powell, S.M., Humphries, R. and Eston, R.G. (2006). The effect of accelerometer epoch on  
physical activity output measures. Journal of Exercise Science and Fitness. 4: 51-57.  
Ruiz, J.R; Rizzo, N.S; Wennlof, A.H. (2006). Relations of total physical activity and intensity to fitness and  
fatness in children: the European Youth Heart Study. Am J Clin Nutr; 84: 299-303.  
Sallis, J. F; McKenzie, T. L; Alcaraz, J.E. et al. (1997). The effects of a 2 year physical education program  
SPARK) on physical activity and fitness in elementary school students. Am. J. Clin. Nutr. 87(8) 1328 – 1334.  
Shetty, P. S. (1999). Obesity and Physical Activity. NFI Bulletin, April.  
Shingo, N. and Takeo, M. (2002). The educational experiments of school health promotion for the youth in  
Japan: analysis of the ‘sport test’ over the past 34 years, Health Promotion International. 17(2): 147-160.  
Simons-Morton, B.G; Mckenzie, T.J; Stone, al. (1997). Physical Activity in a Multiethnic Population of  
Third Graders in Four States. Am J Public Health.87:45-50.  
Song, T.M; Find all citations by this author (default).  
Stella,S.G; Vilar, A.P; Lacroix, C et al (2005). Effects of type of physical exercise and leisure activities on the  
depression scores of obese Brazilian adolescent girls. Braz J Med Biol Res. 38(11):1683-9.  
Stratton, D. C; Boddy, L. M. et al. (2007). Cardio respiratory fitness and body mass index of 9–11-year-old  
English children: a serial cross-sectional study from 1998 to 2004 International Journal of Obesity. 31, 1172–  
Telford, A; Salmon, J; Timperio, A and Crawford, D. (2008). Examining physical activity among 5- to 6- and 10-  
to 12-year-old children: The children’s leisure activities study. Pediatric Exercise Science. 17(3): 266-280.  
Tremblay,M.S; Barnes,J.D. (2005). Conquering childhood inactivity: is the answer in the past? Med Sci Sports  
Exerc. 37(7):1187-94.  
WHO (2003). Diet, nutrition and the prevention of chronic diseases. WHO Technical Report Series 916 Geneva:  
World Health Organization.  
Wickel, E. E; Eisenmann, J.C. (2007). Contribution of youth sport to total daily physical activity among 6- to  
2-yr-old boys. Med Sci Sports Exerc.39(9):1493-500.  
Wiecha, J.L; Peterson, K.E; Ludwig, D.S. (2006). When Children Eat What They Watch Impact of Television  
Viewing on Dietary Intake in Youth. Arch Pediatr Adolesc Med.160:436-442. Physical Activity Pyramid.  
Yeung, J; Wearing, S.C; Hills, A.P.(2007). Enivronmental factors and physical activity in children. In Children,  
Obesity and Exercise. (eds). Hills, A.P; King, N.A; Byrne, N.M. Publ. Routledge.  
Zahner, L; Puder, J.J; Roth, R. et al (2006). A school based physical activity program to improve health and  
fitness in children aged 6-13 years (“Kinder Sportstudie KISS”): study design of a randomized controlled trial.  
BMC Public Health; 6:147  
Zarrouk, F; Bouhlel, E; Feki Y. (2009). Physical activity patterns and estimated daily energy expenditures in  
normal and overweight Tunisian schoolchildren. Journal of Sports Science and Medicine. 8, 83 – 88