Smooth Fitness is the best online retailer for Treadmills

If you’re considering one of the latest treadmills, there are many factors to think about before bringing one home, please read our Treadmill Buyers Guide . Belt size, speed, horsepower, displays, deck cushioning—all of these aspects can make a difference in whether you’ll keep walking or running on the machine.

Look for a motor with a continuous-duty rating of at least 1.5 horsepower. This is the bare minimum; anything less will give you an inferior workout and is likely to break down and need repairs. If you plan to run, not just walk, on your treadmill, or if you weigh more than 180 pounds, don't settle for less than 2hp. A DC-driven motor (as opposed to AC) gobbles less power, and is less expensive to repair should trouble arise. Experts say you should avoid manual treadmills altogether.

The two-ply belt should be no less than 18 inches wide and 48 inches long. According to Prevention Magazine walking editor Maggie Spilner, a smaller belt forces the average walker to shorten his or her stride. If you have long legs, you must have a belt longer than 48 inches. The American Council on Exercise recommends a 49-inch belt. All the models in Fast Answers include belts that are at least 20" x 54".

The deck should be at least a quarter-inch thick. The best decks are low-impact structures that absorb shock by flexing under your foot when it strikes the belt. If you have injuries like shin splints or recurring back/foot problems, this feature is a must.

The display panel should show all the necessary information at once, preferably in large, easy-to-read numbers. A scanning display, which rotates the readouts through one window, can produce a feeling of disorientation because you have to keep your eyes on the panel while you work out. Make sure the display shows speed, distance covered, incline and time elapsed.

Push-button controls are better than dials or switches. Sliding switches can be imprecise and stubborn to move. You should be able to push control buttons while you're running.

Welded frames are sturdier than bolted frames. The less jarring and jiggling, the better. Although frames are generally made of steel, treadmills costing $2000 and up (for example, the PaceMaster ProElite) are sometimes constructed of aircraft aluminum. These models absorb shock, are light and easy to move, and don't rust.

Some exercisers think handrails are a nuisance because they impede arm movement, but experts say they're necessary for safety. Rails should be long enough for you to reach without having to walk too close to the front of the treadmill. Note that some models, like the Life Fitness T3, don't have side handrails at all.

Beginners should look for an incline of at least 10%. A treadmill's maximum incline should suit your fitness level. According to the American Council on Exercise, beginners will do fine with an incline of up to 10%, but advanced exercisers may want a treadmill capable of 15%. Test the machine's stability during incline mode before you buy.

Walkers need a speed capability of 5 mph, runners need 8 to 11mph. The starting speed should be slow (0.1 to 0.5 mph) to avoid injury.

Look for a safety key if you have kids. Children and pets should not be able to start the machine by accident. Experts say refrigerator magnets can start some machines that use a magnetic key.

Go for a model with a panic button or automatic shutoff. If you slip or get into trouble, the power should cut off instantly by means of a button you push or a tether attached to your clothes.

Read the fine print on the warranty. If you're heavier than the warranty specifies, the contract may be void. The frame should have a lifetime warranty against manufacturing defects; other components should come with a warranty of one to three years for parts and labor. Avoid 90-day warranties. Finally, make sure you can return the treadmill if it doesn't suit you.

Keep your treadmill clean. Dirt and dust are the primary early killers of treadmills, so weekly dusting is a must to ensure your machine has a long life.