If it is shin splints you're getting then I share your pain, I get them constantly and it really put me off cardio. Sounds pathetic...but I now run on the spot in my room...I find it doesn't hurt as much, and although it's probably not as intense, but heartreat is still up and the sweat still comes off, and if that happens I feel it's a good workout regardless.
You could try alternative exercise like dancing or swimming if you have cheap access, not that I'm trying to put you off

It sounds like it's not bothering you enough to want to stop tho, so that's gr8
The trainers thing apparently helps though. When the winter's over I'll probably get some new ones and force myself to get back into real running
