Pain in my legs

Lately I've been getting achey pains in my legs, kind of like pinched nerve pain. I'm thinking it's because I'm not exercising. When I used to run regularly I didn't get them, but when I get lazy it comes back. Occasionally on Freecycle I see people offering treadmills and ellipticals and stationary bikes, but I never go for it because I don't know where I'd put one or if I'd even use it, but I'm thinking the next time I see an offer for one I might see if I can get it.