Nice post @katherinalive. It is educative. But the types of the sports that could be done at home may require money as well. Bearing in mind that most individuals that could not afford money for gym may not also be able to afford sports at home. But specific exercises could replace sporting at home; walking for minutes...
sport is not necessarily something professional. I think that any person is able to do home stretching, shake the press, and push-ups. This over time will only give a head start in physical form.