Does rollerblading help improve running?

It won't help at all. If your having problems with your cardio (getting winded while running) then it will help. But as for building the muscles that you need for running it will not help. Rollerblading is very similar to skating and in skating your legs don't go straight forward and back as they do in running. Instead they go out on an angle and push off. This means that you aren't using all of your running muscles and if your just looking to get better at running then I'd start running