Thought I was about to have a heart attack and most of the running I spent as a sturdy march. Should I repeat week 1 or continue with week 2? I am doing the 12 week fitness plan, c25k combined with strength and flex, however I am a very big girl with a huge bmi..........I also do aerobics at least 4 times a week. I have extreme pain in my legs below the knees at the bag and extreme heat throughout my body. Any advice would be great.