First identify which muscle you wish to lengthen. Hold the stretch for 1 to 2 seconds at the end of your natural range of motion. Return to start position. Exhale as you contract the agonist muscle and inhale as you return to start position. So I know how critical stretching is both before and afterwards to prevent injuries.
Training can be very specific.
It usually takes about three months to change your body composition. Don't just eliminate carbs. You will lose your muscle glycogen. The Wharton Cardio-Fit Book has fantastic information that will help you. I have planter fascitis in both feet and my job requires standing on a cement deck for 5-6 hours a day.