I was really excited when I got the 30 day shred but my knees started killing me and I had to stop doing it everyday- I run as well but it has never given me knee problems, unless I run over 6 miles. So I have limited my jillian michaels time to maybe once a week and I switch it out with other DVD's like Jackie (I don't remember her last name) but her workouts are great and never give me knee trouble. I have hardly ever had knee trouble with anything I do so it frustrated me that a short workout could hurt so bad. I'm sure it works for alot of people though- good luck
I *just* finished the 30-Day Shred this morning! I will tell you that I could not make it through the first 5 or so workouts. But the 25 following workouts I could manage. It was exciting to see my progress! One thing I regret (and I will do this differently when I do the Shred again) is that I automatically did the beginner level without even trying the hard level. By Level 3, I could totally do some of the hard stuff! I bet I could have done it sooner if I had tried.
Good luck with it! My endurance has increased tons and my muscles are starting to show up. I look pretty good if I do say so myself! Let me know if you need encouragement!