Questioning walking power

Any exercise is going to help burn calories. The more intense the more calories. So walking isn't going to burn a lot, but it will burn some.

I too am asthmatic. I've never gotten relief from inhalers, so I've had to really watch it and have learned the signs that my body is giving me. Try different kinds of sports!!! I know it might sound strange, but there are certain cardio activities that are just more tolerable - specifically the ones that give YOU more control over as many possible aspects. For an example - I can't run for long. Running/Jogging has to be one of the hardest on my lungs. I can't help but think that is true for many asthmatics. When people think cardio, I think most people would think of running first. So for somebody who is asthmatic to start running and not be able to do it, most just stop there. Try the elliptical! It is a bit lower impact than running and I think (just my own feelings) that because you aren't thrusting your body like you do when you run, that I can do it longer. Not to mention you have total control over the incline and level. I actually don't even use the incline myself. I know a lot of people are really into going slower with a large incline but I increase the difficulty by using the level instead. Try biking, try rowing, try hiking up a hill, try boxing, try walking quickly up stairs, etc... And even with asthma it is possible build up your lungs strength. The less I do, the less I'm able to do without an attack. And visa versa.

With all of that said... the disease manifests in different ways for different people, so listen to your body.