Swimming in Bogota (Bogotá)

Does anyone have any hints about where to go to swim (work out) in this city? I tried Colsubsidio, but their pool is only open (and not full with classes and such) from Protected content weekdays and on weekends, and I can't make that time. I looked into the Complejo Acuatico near Simon Bolivar, but it seems that they require a cedula for foreigners and a letter from a doctor. Is there any easier way? Because I'm not sure how or when I'll be able to get a cedula, but I would like to be able to work out in the pool.

Thanks!