By Andrew Downie
RIO DE JANEIRO (Reuters) - There are 28 sports in the Rio Olympics but if the first few days are anything to go by, soccer will be present at all of them.
At stadiums and arenas all across the city, Brazilian fans have raucously shouted support for clubs Fluminense and Flamengo, waved Cruzeiro and Sao Paulo flags, and paraded around in the shirts of Gremio, Botafogo, Internacional and many more.
They have brought a football-vibe to the Games, passionately cheering on their own side and often booing their opponents.
In moments of silence, fans have screamed their support not just for the tennis player or the boxer, but for Corinthians and Palmeiras.
Hearing "Go on Corinthians!" is almost as common as hearing "Go on Brazil!"
Brazil is the country of football, a sport that dominates all others every day of the year.
"No one has a shirt for the fencing guy," said Marcelo Pinheiro, an Atletico Mineiro fan who came to the tennis dressed in a Brazil shirt with an Atletico badge where the usual shield should be. "Everyone watches football."
Brazilian football crowds are low -- the average league attendance is only 14,400 -- and many fans are scared off by violence, poor public transport, wall-to-wall live broadcasts and inconvenient kick-off times.
Because they did not go to the games, they wanted to show off their support wherever they could, Pinheiro said.
"Brazilian men and even women, they have their teams but not everyone goes to the games so when they have a chance to show their support in a safe surrounding they take that chance," he said.
Another reason is related to Brazil's famous informality: wearing a football shirt is a way of connecting with the world.
"It's a way of breaking the ice," said Daniel Pitta Marques, a fan of Socrates's old club Botafogo from Ribeirao Preto.
"You identify people who like football. Other people come up to me and ask me about Botafogo or if I'm from Ribeirao Preto. Or people just shout out, 'Hey Botafogo'!"
Maybe the best reason is one every football fan will understand.
"One of my motives is simply to show off my team," said Pitta Marques.