I want to start biking again. Do you know any safe spots in the Makati or Mandaluyong area to bike that's not too polluted? Thanks!

You can try cycling around Ayala Triangle. The place is nice and there are a bunch of trees surrounding the area so even if you're inside the hustling and bustling city of Makati, you can somehow feel the fresh air around. But if you plan to go a little more hardcore, you can visit Fort Bonifacio tracks, although it's only near Makati. It's located at Taguig. You can check this blog post from bisekleta.ph to know more about this "Army Trail." http://www.bisikleta.ph/2009/08/biking-in-manila-fort-bonifacio-tracks.html