Characteristics of physical activity programs in the Brazilian primary health care system oleh Grace Angélica de Oliveira Gomes, Eduardo Kokubun, Grégore Iven Mieke, Luiz Roberto Ramos, Michael Pratt, Diana C. Parra, Eduardo Simões, Alex A. Florindo, Mario Bracco, Danielle Cruz, Deborah Malta, Felipe Lobelo, Pedro C. Hallal