Nope, frenchfancy I really cannot get hold of any running shoes. I've looked into it, but it's spring festival at the moment so the only shops open are big foreign chain food shops, a few supermarkets and a few fashion clothing shops, so I'd have to wait until next week to try and find some running shoes anyway.
It's not like the UK where you can pick up a pair of OK runners in Tesco. What look like running shoes in the supermarkets and fashion clothing shops are very cheap quality (I used to think 'made in China' meant not that great quality, but now I know 'made and sold in China' is much worse) and are not really meant for sport. I tried a pair on and they were awful. My ready-for-the-bin shoes provide more support and cushioning than the things I tried on in the supermarket, plus my feet slopped about in the supermarket shoes because they were too wide.
I'd need to find a proper sports shop but I've no idea where to find one. I've not seen one in the over 5 months I've been here. That doesn't mean there aren't any, just means I have no clue where to look. China is pretty backward so it's not a simple matter of just googling it. (It's as easy to google where places are here as it was to google places in the UK in the 90s. Plus google often gets blocked here anyway.) If I did get a pair I'd only be able to use them for a couple of weeks before I come home anyway. I'm already having to decide which of my belongings to throw away and which to take home because of the weight limits for luggage when flying. A heavy item like runners wouldn't make the cut.
This is all moot though really as I have about 600 yuan (about £60) left to live on for the next 19 days so I probably couldn't even stretch to a cheap pair while I'm out here. Most places don't take foreign plastic.
Ooh, sorry that's not meant to be a rant or anything. 
I've just been finding myself increasingly irritated by how limiting it is to live in China. Especially when I know that if I'd been home I'd've just nipped out to Tesco to pick up a cheap pair to get me started and then, having googled running shops I would have gone into them to have a look and try on a few pairs then spent hours anally careful researching which type of shoe is best for me and trying to find the best pair I could afford online.
That said, I have spent the last 4 hours having a look at various running sites and sports clothing websites to find a half decent pair that are right for me to get sent to my home address so that I can sling my had-it shoes before flying home and have a nice shiny new pair of proper runners to use for my first run in the UK. 
Finding the process a little daunting and scary actually.
So far I haven't had any pain from running in my non-runners. Hopefully I'll be ok for my 7 remaining runs in China. The only other option is not to run, but I know if I do that I won't start up again when I get home.