Switching up cardio: running or low impact?

[backat1]

Hey guys, I am recently back to the gym, and you can see my stats on the newbie forum or in my profile. I am going to start AM cardio, since my main goal at the present is to cut down some fat that I've stored in the past year.

I have always done elliptical machine cardio, and I can easily keep my HR at 170-182 on there. I like high intensity, and get too bored when I'm not either really working or doing some sort of HIIT. I may actually even be overdoing it.

Despite the fact that I have about 3 years experience with an elliptical and know exactly how my body reacts to it, I have NO experience with running or any sort of sports, and I am terrified that I am going to injure myself if I switch over or bore myself to death if I do not. I searched around on the forums for a comparison between high and low impact cardio, but could not find anything.

At 6'3 and 290 lbs, my knees can't love the concept of running, and to be honest, despite my endurance, running HURTS me, and it even did when I was at 195 lbs. Is there any intro to running that I should be doing to gradually increase the strength in my knees/legs so that I can minimize chance for injury? I had a friend that suggested yoga and possibly doing 5 days low impact, 1 day running for a few months. What do you all think?

Edit: Also, is cardio PWO better or good to have in addition to AM cardio? I hear a lot about PWO cardio lately, and I don't remember reading a lot about that when I was doing all my research before.

[eatrainrest]

To those who dont know

[backat1]

Thanks for the link! That answers the last question and a very good read.