Its a tricky one this. Up to the age of about 11 i am all for girls and boys playing in mixed teams in ALL sports. In our year 3 class we have one girl who is better then pretty much all the lads at football and when shes not playing for the girls netball/hockey/football team she'll play for the boys. I personally think the boys should be on mixed teams with the girls playing netball and the girls should be playing football mixed with the boys at that age. Whyever not? Surely the aim of sport at that age is to develop skills in fun games and often the girls are just as tall/strong as the boys if not more so when younger as they mature faster. Games like netball are excellent for boys ball skills as well as girls and although its socially acceptable for girls to play so called 'boys sports' its seen less acceptable for boys to play 'girls' sports though i know in state schools they often have mixed netball teams and i believe that in places like Australia they have many mens netball leagues.
After the age of 11 things are trickier with the height/weight/strength difference so it becomes more of an unclear issue. I often played football with lads twice my weight and height and i didn't mind if they went in for fair tackles, if i did i wouldn't have played (i did object to them just lifting me out the way though!
) Non contact sports such as netball for example could still be mixed but as much as i'm for womens rights Lil mo is correct on something like the rugby pitch it would become dangerous.