I used to run a lot. My exercise of choice. But due to children took a break. I suffer sciatica like pain now and then bouts last a while then go. Went for nice run the other day enjoyed it but after I've really suffered with bad back. And actually it's happened after work out DVD's too so should I do some low impact exercise like swimming instead or will this get better as I get fitter? It's hard to keep at training wen each session floors me for a few days!