The SCW believes there is now a need for positive discrimination towards girls' sport, with schools being at the forefront of such a drive. Research by the SCW has shown that PE teachers are frequently ill-prepared to deal with the difficulties girls face, and it wants to see better in-service training.
The most widespread criticism girls have of PE teachers is that some favour more able pupils and undermine the confidence of the less talented. Money and equipment tend to go into boys' sport.
Some girls found teachers were insensitive about their developing figures, and they resented having to wear unflattering kit. One 15-year-old said her games teacher told her: "No excuses, girl. You could do with losing a few pounds. "
The Sports Council says there needs to be more innovation. It suggests that peripatetic PE teachers could work with primary pupils or primary schools and form links with neighbouring secondaries for PE.
But the report, Changing the rules: Women, girls and sport, recognises that links have to be made with local communities to ensure children continue taking part. The number of girls involved in sport slumps as they grow up.
Dr Huw Jones, director of policy planning at the SCW, says: "We have found that girls are missing out on sporting opportunity. They are at a significant disadvantage compared to boys. There are not the same curricula and extra curricula activities for them" The SCW will be working with schools, local authorities and Government bodies over the next few months to overcome the barriers to girls. There are also attitudes in society to be addressed, the council says. The report believes certain elements of the media tend to trivialise or ignore women's sport. Sportswomen are often discussed in terms of their sexual desirability or domestic roles. And there are too few female role models.
Dr Jones says: "This belief that sport is ultimately more important for boys and men leads to female sport carrying less prestige than men's and to less interest in sport among the female population."
Sports offered in schools tend to still be gender segregated with boys playing rugby, football and cricket and girls netball, hockey and rounders. If girls do take part in so-called boys' games, they risk having their sexuality questioned.
And while this report focuses on Wales, the Sports Council in England is carrying out similar work and says its findings are likely to be similar. According to a spokeswoman: "We are making sure our sports programmes are gender equitable and the education and training issues needed by girls are addressed. We have been working towards getting more women and girls involved in sport for years."
Lucy Parsons, 17, is an international athlete who has represented Wales, and knows the difficulties girls and women face.
"It's frustrating, but it makes me more determined to do better. A lot of girls drop out though because they are not taken seriously. At school in the beginning when I started doing well they were behind me, but really they are more interested in boys and their rugby and football. For a girl to achieve something you have to do so much more," she says.
Her coach, Mark Thomas, the sprint trainer for Wales, says it is difficult to get females into sport and keep them there. However, he adds that there were now many more opportunities in athletics, with events such as the pole vault and triple jump now open to women.
Julia Longville is an HM inspector in Wales and a PE and sport in-service training co-ordinator in schools. She wants to develop links with sports clubs and give girls the chance to try out many sports.
"In the most successful schools girls have been involved in the decision making. There is a move away from competitive games and the sort of options that are popular include aerobics and aerobic-related activities," she says.