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If you've ever wondered if an elliptical trainer is a worthy piece of workout equipment, let us tell you: Yes. That's Fit.ca agrees, calling it "a great machine for an all-over body workout."

It's a combination of a stair climber and a cross-country ski machine, with pedals that move in an oval-shaped motion, and it works both the lower and upper body, with its forward and backward leg motions and its movable handlebars. On its own, an elliptical workout will help you torch through 300 to 400 calories (for a moderate to vigorous 30-minute session). With a little extra push, you can really up the burn.

You can increase your intensity and your incline, for starters -- every two minutes for 30 seconds to one minute; then bring it back down. Or grab some hand weights and swing your arms while you motor along, you'll use more muscle this way. You can also change directions -- forward works the quads; backwards gets the hamstrings -- which will help you work out longer. Although, backwards might not be better -- but Liz has more on that.

To figure out how hard you need to work to burn the calories in cookies, sandwiches, nuts and more, check out this AOL Health exercise estimator.