This report highlights relevant research and expert opinion on girls' involvement in physical activity and sport. Research findings revealed: (1) more girls are participating in a wider array of physical activities than ever before; (2) regular physical activity in adolescence can reduce risk for obesity and hyperlipidemia, increase bone mass and reduce risk of osteoporosis in later life, and reduce stress and depression; (3) exercise and sport participation can enhance mental health by improving feelings about body image, self esteem, and enhancing self confidence; (4) poverty substantially limits many girls' access to physical activity and sports; (5) excessive exercise and certain forms of athletic participation can lead to eating disorders; and (6) barriers to positive experiences for some girls are lack of opportunity, gender stereotypes, and homophobia. Study findings suggest a number of conclusions and practical recommendations, including: girls should be encouraged to get involved in sports at an early age; specific mechanisms which enhance girls' opportunities to be physically active must be developed and supported; physical educators, exercise leaders, and coaches are in a primary position to recognize disordered eating patterns; girls and boys should work and play together from an early age; coaches and physical educators should give girls equal access and attention; and professionals must actively intervene in the face of discrimination. Directions for future research are also outlined. (Contains approximately 300 references.) (ND)