As any late-night TV enthusiast or insomniac can tell you, the overnight airwaves are full of infomercials promising you easy ways to shed pounds in just "minutes a day."

But wait, there's more.

The reality is many of the workout products being pitched in late-night infomercials overpromise at best and simply fail all together at worst.

Sure, everybody loves getting something for nothing, but when it comes to "as seen on TV" fitness equipment, remember there's no such thing as a free lunch.

It's true that even the most useless workout products out there might provide some benefit when paired with diet and exercise, but hardly any of them are the miracle fat-melters society seems to be yearning for.

Just something to keep in mind the next time you reach for the phone while watching an infomercial for one of these five worst workout products ...

woman using Shake Weight

No. 5: Shake Weight

If you haven't made fun of the Shake Weight and its slightly suggestive yet hugely popular infomercials, you're in the minority.

More than 4 million people have watched the Shake Weight ads on YouTube, and even more tuned in to see the workout product mocked on "The Ellen DeGeneres Show" and "Saturday Night Live."

The Shake Weight is a 2.5 pound spring-loaded dumbbell device that users grip two-handed in the middle and shake up and down. But our words fail us; watch the ad to truly grasp the ludicrousness.

While the ad promises a full-body workout in "just six minutes a day" through something called "dynamic inertia," the oxymoronic, seemingly made-up term has been ridiculed by various fitness experts and authors.

The jury may still be out on whether the Shake Weight delivers on its promises, but for all the joy and laughter it has provided us, we'll give it a break for now.

The Hawaii Chair workout product

No. 4: The Hawaii Chair

The world of infomercial workout products is dominated by promises of results without much actual work, and no product illustrates this more than The Hawaii Chair.

What is there to say about a product that claims, "If you can sit, you can get fit"? Are we really that lazy, America?

The Hawaii Chair is a chair with a 2,800-rpm motor strapped underneath it. The base of the chair gyrates you around in a hula motion that supposedly tones muscles.

However, the best thing about The Hawaii Chair is its promise you can shape your body while at work, keeping fit while you sit at your desk. Supposedly you can answer the phone, do paperwork and conduct meetings all while gyrating from the hips down. Good luck with that.

Here's hoping your workplace archenemy in the next cubicle over gets one of these, because laughter really is the best revenge.