Weeks 1 and 2 Walk 10 to 15 minutes, most days of the week. Stretch your calves every day to prevent heel pain. (Stand at arm’s length from a wall, and gently lean into the wall, keeping your feet flat. Hold for 10 to 30 seconds.) [sidebar] Weeks 3 and 4 Walk 20 minutes, most days of the week. Walk on your heels, and tap your toes for a few minutes as a warm-up to stretch and strengthen your calves and shins. Weeks 5 and 6 Walk 30 to 45 minutes, most days of the week. Do walking lunges to strengthen your thighs and prepare for hills and hikes. (Take a giant step forward with your right foot, bend your left knee almost to the ground. Keep your right knee directly over your ankle. Pressing into your right foot, stand back up, bringing your feet together. Repeat, stepping with your left foot. Do 10 to 20 lunges with each leg, two or three times a week.) More from Prevention: Run Your First 5K
