I have not done much sport lately because I never really found good paths for roller blading (inline skating) here in Santiago.
Today I found out about that there are streets closed for cars in La Reina just for cyclists every sunday. The even better news is that this will be extended to La Florida, Lo Prado, Providencia, and Santiago. I will let you know once I have done it. I will be back in Chile beginning of June. More info on the CicloRecreoVía here.
There is more info on the Spanish version on the site including a map. Looks like Las Condes also closes a street on Sundays. http://www.ciclorecreovia.cl/ciclorecreovia-las-condes/