By ratifying the Convention, governments become legally bound to implement the rights therein.
Sport can be used for messaging, for example, making the connections between shin guards or a helmet that protects you, and protection in terms of HIV and AIDS. There has also been a very active program in Africa called 'Kick Polio out of Africa,' where soccer players have spoken out in terms of polio. There is also going to be a swim for malaria.
For example, UNICEF works with governments to change legislation such as in India where a law was passed raising the age of compulsory school completion to keep children in school and away from the workplace for longer.