References
- Centers for Disease Control and Prevention. 1997 . Guidelines for school and community programs to promote lifelong physical activity among young people . Morbidity and Mortality Weekly Report , 46 ( RR-6 ) : 1 – 36 .
- Powers , H. S. , Conway , T. L. , McKenzie , T. L. , Sallis , J. F. and Marshall , S. J. 2002 . Participation in extracurricular physical activity programs at middle schools . Research Quarterly for Exercise and Sport , 73 ( 2 ) : 187 – 192 .
- U.S. Department of Health and Human Services. 1996 . Physical activity and health: A report of the Surgeon General , Atlanta , GA : Centers for Disease Control and Prevention .