1. National Federation of State High School Associations: 2004–2005 High School Athletics Participation Survey. Indianapolis: National Federation of State High School Associations; 2006.
2. National Collegiate Athletic Association: 1981–1982–2004–2005 NCAA Sports Sponsorship And Participation Rates Report. Indianapolis: National Collegiate Athletic Association; 2006.
3. Beard J, Tobin B: Iron status and exercise. Am J Clin Nutr 2000, 72(Suppl):594S–597S.
4. Shaskey DJ, Green GA: Sports haematology. Sports Med 2000, 29:27–38.
5. Dill DB, Braithwaite K, Adams WC, et al.: Blood volume of middle-distance runners: effect of 2,300-m altitude and comparison with non-athletes. Med Sci Sports 1974, 6:1–7.