and, no lie, my legs felt like they're made of lead.

So, GT - who has tips for getting into running? I was getting pretty good at it a couple years ago. I know about Couch to 5K - a 5K isn't really my goal, I just want to be able to jog a few miles because it makes me feel better. How do I do it without killing myself and fucking up my knees?

Also: Who knows good ab exercises for someone with a bad back? This belly of mine has to go.

ETA: Also also: If I want to start learning yoga, are there good videos available online? Preferably for free?