Liz Neporent is a diet and fitness expert and co-author of "The Fat-Free Truth." She regularly appears on national TV programs and is the president of Wellness 360, a New-York based wellness provider. You can also follow her on Twitter @lizzyfit.

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Does the thought of struggling up a hill during your workout make you want to run the other way? Perhaps you're suffering from hillophophia, a common disorder that makes you quake with fear every time your feet meet with an incline. If you are so afflicted, relax. The secret to running and walking up hills is not to let them get the upper hand.

The thing to keep in mind is that hills are not the enemy. Treat them as an opportunity to improve your fitness level and pick up the pace on calorie burn. For every additional 5 percent of grade (a modest uptick in the landscape), a 150-pound exerciser will burn an extra three to five calories per minute.

If I've "peaked" your interest, let me give you some advice on how best to incorporate some hills into your workout. You can follow the formal program I outline below, but in general, you'll get the most bang for your buck by mixing both long and short hills into your workout. I consider longer hills any incline you stay on for at least two minutes, whether you are outdoors or on a treadmill. These teach your body to work harder for longer periods of time and increase your body's ability to use the oxygen you breath. Shorter inclines improve your ability to perform quick, explosive bursts of activity -- which translates into more strength, speed and power. You should pick up the pace and intensity when you do these so you make the most of them.

Now a few words about form: Runners should lean slightly forward and let the hips and buttocks assist the thighs as much as possible. Use an arm swing that's relaxed, perhaps a little more forceful than usual, but not over-exaggerated. Rather than taking longer strides, take quicker, shorter ones, lifting your knee no higher than 6 inches. The idea is to bustle, not bound, upward. Walkers should practice similar form but use a larger arm swing, much like the arm movements used in cross-country skiing.

Travel down a hill in a relaxed glide rather than careening out of control until you reach the bottom or trying to fight gravity by leaning back and putting on the brakes. Lean forward slightly so that your torso stays perpendicular to the road surface and take small, fast steps, letting each foot strike flow smoothly into the next.

My 2 cents: If you're just beginning an exercise program, skip the hills until you're in better shape. As your fitness level improves, start with gently rolling hills and gradually add steeper upgrades.

For a real challenge, try this "hill repeat" workout once a week: Warm up for five to 10 minutes with a brisk walk or easy jog over level ground. Find a hill a few hundred yards long that's steep enough to give you a workout but not so steep you can't make it comfortably to the top at your normal pace for an incline. You'll need a watch with a second hand to time yourself. Run or walk hard up the hill, then jog or walk easily down to the bottom. Rest for the same amount of time it takes you to go up to the top and back down again. Keep moving. Try marching in place or walking in a circle. Repeat three or four times. Cool down exactly as you warmed up.

Now for your 2 cents: I want to hear from you after you've gotten "high" on hills. Also, If you've got your own hill workout, especially if it's for cycling or some other sport I haven't talked about, please share with the group.

Hey, I've got one more copy of Chris Freytag's DVD, Walk Yourself Fit to give away. If you're interested in trying out a unique way to add walking and running to your routine, be the fifth person to tweet me today and it's yours! (twitter@lizzyfit.)

To calculate how many calories you burn doing hills or any other type of exercise, head to Calorie Control. Then sharpen your walking and running skills.