I'm only on Week 2 but my calves (sp!!) feel really uncomfortable when I'm running. They feel achey from the word go. What could cause this? I make sure I do the warm-up and warm-down walk each time, and always make a point of stretching my calves out when i get in I think it's gonna be my legs not my lungs that cause problems but I soooooooooooooo want to do this. Any suggestions gratefully received. Thanks.