So I have been doing a great job with my new “Healthy Lifestyle” working out 5 days a week. I run outside at least 3 days a week. My knees are now KILLING ME!!!! Why? Is it from running on the concrete? I also deal with my stomach aching when I run too. Again……WHY? I’m trying to do well by doing this running/walking because I know it’s a great form of exercise, but why is my body trying to break down on me?