I see a lot of fitness products and exercise machines advertised on TV. I'm tempted to order some of them, but I wonder -- how do I know if they're any good? Do you have any advice about buying these machines?

To listen to exercise equipment infomercials, you'd think that getting in shape was the easiest thing in the world. Just buy the product and the pounds will peel away.

If only it were that easy!

The miraculous assertions made on fitness product infomercials are often wild embellishments. Some are flat-out lies. Last year, the Federal Trade Commission (FTC), in a campaign dubbed Project Workout, procured legal settlements from marketers of several popular exercise products for making exaggerated claims in their advertisements.

Take the complaints filed against Abflex, an abdominal exerciser, LifeCycle, a stationary bicycle, and the Crosswalk treadmill, a motorized treadmill with an arm exercising attachment. The FTC declared that those products could not support claims such as "spot reduction in just three minutes a day" or "burns over 1,000 calories per hour with ordinary use." Many of these ads used testimonials ("I went from a size 12 to a size 8!") that did not represent typical results or that falsely claimed to have scientific studies supporting their assertions. All three companies settled with the FTC and have been prohibited from making those exaggerated claims in future ads.

Although the FTC crackdown is a good start, many exercise-equipment ads still make dubious weight-loss and spot-reducing promises. (The FTC can only go after individual ads and cannot issue blanket injunctions.) Americans continue to spend $2.4 billion a year on get-fit-quick schemes. So before you find yourself reciting your Visa number to Operator 26, let's decipher some of the more common exercise infomercial claims and see how they hold up under scrutiny:

• Lose 30 pounds in 30 days. The fact is, no one can accurately predict how much or how fast you'll drop weight. You should be wary of anything that guarantees quick, permanent results.
• Melts fat from your hips, thighs or stomach. There is no way to diet or exercise away fat from a specific part of your body. This so-called "spot reducing" -- one of the most oft-mentioned pledges you'll see in ads for fitness equipment -- is simply a physiological impossibility. Period.
• No sweat, no effort. No dice. If you're not working hard enough to work up a sweat, you're not working hard enough. Exercise doesn't have to be grueling and painful, but if it's effortless, don't expect results.
• Total-body workout. On many machines, the arm mechanism is linked to the leg mechanism, so even though your arms are pumping, they're just along for the ride. You aren't getting a better workout, and you aren't necessarily burning more calories.
• Fit in minutes a day. How much fitness can you expect from working out just a few minutes a day? Not much. Most reputable fitness experts maintain that you need to exercise aerobically for at least 20 minutes a session to derive cardiovascular benefit and even longer if your main goal is weight loss. An infomercial for one complex-looking exercise contraption asserts that you could get in shape with four-minute workouts. If that were true, the $800 price tag would be worth it.

So the bottom line? You'd never think of buying a pair of shoes without trying them on, or putting a deposit on a new car without taking a test drive. The same holds true for fitness gadgets that you've only caught a glimpse of on TV. Don't let your natural defenses be broken down by a string of tantalizing claims for "thinner thighs in 30 days" or "the body you've always dreamed of," and don't plunk down your hard-earned money for a fitness product that sounds too good to be true.

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