Since my objective when I go any cardio is to simply keep my heart rate up for an hour I don't really mind anymore that my pace is terrible. I am older, I get knee and foot problems easily but I still will hunker down and get the cardio done anyway because I hear the excuse of "my knees are bad" from far too many people who also just happen to be the same people who are in terrible shape. It is an excuse, not a prevention. I'm not saying that people with genuine injuries should suck it up and go exercise anyway, but if you are a fat ass and you are talking about how you don't run or walk because of undiagnosed "knee problems," you are likely just looking for an excuse to remain lazy.
My runs these days are nor focused on mama speed at all, but instead just getting out there and moving doing something, anything, for an hour several times a week.
I head out the door, once again the most difficult part of the run being exactly that part of it, and will have my tunes on or a podcast and normally will run/walk/jog the first km or so. Then, when I feel the urge to stop, I will go another 100 meters or so and then walk fast. I never stop until I am actually done for the day.
One thing that I was quite happy with here was the fact that I went a bit further than I had actually planned on. Well, I shouldn't say "planned" because I never really have a plan. Even though I have lately been focusing on preventing precisely this, I ended up starting out too fast and then tapering off later on.
I suppose it wasn't that bad this time because km's 1 and 2 are relatively the same. For guys taller than me, those first two would probably be a powerwalk and for me it is just a light jog. I don't try to go fast, I just try to keep moving. Towards the end I am doing more walking than jogging, but I do it intermittently and don't really have a plan. I run until I feel like not running anymore and then I switch back to fast walking.
If that calorie burn is anywhere near accurate, that is a good amount of calories to burn in an hour. That's 3 beers I've earned right there!
So get out there and do something. This is not difficult and as I have said many many times before the only part of it that is truly difficult is the part where I make the decision to put my trainers on and open the door to my apartment to go outside.