A couple of years ago I changed my workout to all bodyweight exercises. I was a lifelong weight lifter, not necessarily a bodybuilder, but I always enjoyed lifting weights. One thing I purchased for this new venture was a weighted vest, as I had heard good things about how they enhance your workout.
What I like about it is it fits snug around the upper torso so, even when running, it isn’t bouncing all over the place. Adding that extra weight while running/walking will increase the load transmitted through the bones, which will increase the bone density. And that added weight will increase the intensity of your cardio workout. When you put one on to do pull-ups and push-ups, it will take your strength movements to a whole new level!
You have a couple of choices here. You can eat more and add pounds to your body to make the bodyweight exercises more challenging, OR get yourself a weighted vest and get to work!