To Walk or Run?
 

So here is my problem: is it better to run for 20 - 25 minutes or talk briskly for 45 - 60 minutes?

I do vigorous cardio on the elliptical/stair machine and bike 3-4 times a week, but I can only run a few miles before my joints (ankles/knees/hips) start to ache and hurt from old injuries and worn down joints. Given that I do cardio, is it more beneficial (metabolism/health wise) to run for a shorter period of time or to walk briskly at an incline for longer?

Any input is appreciated :)

Never mind, just saw the post a week ago. I'm an idiot :)