An elliptical trainer uses a smooth, ovular pattern to give you a fluid workout. Exercise bikes and treadmills are okay if all you're seeking is an elevation in heart rate. And even then, most treadmills are hard on the knees and ankles as those joints are forced to bear the repeated stress of your full body weight with each stride.

The effect of this impact is exacerbated if your gait is off in any way. Lots of runners must combat pronation and supination, or the tendency to bear one's weight on the inner or outer sole of the foot respectively. Over a long period of time, this can lead to spinal problems, knee injuries, hip pointers, even shoulder pain.

An Elliptical Trainer Eliminates These Problems

With your elliptical trainer your motion is locked into place so there's no room for error. Moreover, the machine comes with no-slip foot pads for improved stability and a floor-leveler to make exercising easy, even on unlevel surfaces. A "focus bar" gives you complete control of your regimen and lets you customize your workout for better fat-burning and muscle-building.

And best of all, your elliptical machine blends perfectly with your home's decor. Provided you don't live in a log cabin (or some other throwback structure), your modern elliptical trainer is virtually indistinguishable in any contemporary design. You can't say the same thing for those bright white exercise bikes that scream "health club," even when they're tucked away in your basement.