If most of your walks are merely from your front door to the driveway but you'd like to venture a bit farther, start slowly and work your way up gradually.

Speed: Begin by walking 10 to 15 minutes on flat ground or on a treadmill at a purposeful pace, or complete 2,000 steps (see Monitor Your Walking Progress ). "You want to cover a mile in about 20 minutes. That's not a window-shopping pace," says Mark Fenton, a former competitive racewalker and the host of the PBS series America's Walking.

Goal: Aim to walk at least five days a week. Every second or third week, add 5 minutes. After about two or three months of regular walking, you should be up to 30 minutes. Once you've hit half an hour, add variety to your terrain rather than increasing time or speed. This will boost your enjoyment, encouraging you to keep up the habit.

Posture Perfect: Good posture prevents post-walk aches and pains, and enables you to go faster. Fitness-walking expert Sara Donovan, author of Mall Walking Madness: Everything You Need to Know to Lose Weight and Have Fun at the Same Time (Rodale, $17, www.amazon.com), offers these tips:

Maintain an upright but comfortable posture, with your neck, upper back, and shoulders relaxed.

Minimize the sway in your lower back; don't jut your rear out. Instead, maintain a slight, natural arch in your back.

Gently pull in your abdominal muscles. This helps strengthen your abs while reducing lower-back pain.