A study looking into women's participation in sport says there is too much emphasis on their physical appearance.
The 'This Girl can can't she' study suggests ways to encourage more girls to partake in sport beyond school.
Clothing, changing facilities and unsupportive staff were also found to be barriers to participation.
The research says confidence, stress-levels and happiness should have more significance.
The study, carried out by academics at London South Bank University (LSBU), says changes to marketing campaigns, diversity in advertising and the delivery of physical activity in schools, gyms and sporting clubs can all make a difference to participation numbers.
Sport England says girls' participation in team sports is only 41%, compared to 63% for boys. Only 34% of girls in school years 9-11 enjoy taking part in sport and exercise, compared to 55% of boys.
LSBU suggested more training for physical exercise leaders and PE teachers to allow them to support women and girls better.
It also suggests mixed-gender exercise sessions should focus on skill development and fun rather than competition.
In addition, the study also proposes making homework more physically demanding for children and young people.
It recommends "visits to galleries to see pictures about historical events (for history) or collecting rocks from different parks (for geography) after school".
Rita F de Oliveira, associate professor in sport and exercise science at LSBU, said "big changes are needed" to widen access to physical activity for women and girls.
"One myth is that young women and girls exercise for their looks and that's not what we found," she said.
"They want to release stress, improve their skills and also have fun in the process."
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