Within seconds of meeting Keith McLaughlin and stepping on a late-model Precor elliptical machine, I learned the hard truth: I'd been misusing this ubiquitous, deceptively simple-looking aerobic exercise device for years.

Don't laugh, bucko. You've been messing up, too.

I came to Sports Club/LA, the tony health club in Northwest D.C., to investigate McLaughlin's signature offering: individualized coaching in using the elliptical machine, a device designed to provide a full-body cardio workout without mashing one's knees into putty. He sells a package of three 30-minute coaching sessions on the machine for $135. The result is an odd mix of personal training, upright spinning and advanced sweat extraction techniques.

"Stand up to start, shoulders relaxed and back in line with your hips, and grip the handles lightly," says McLaughlin. "Don't lean on your arms or hunch over. Now, start to stroke and drive through with your heels."

That stance, as opposed to riding on the balls of your feet, helps keep you centered over your hips, meaning your legs -- not your lower back -- will do the work. I set the machine to its "cross-trainer" program, which is designed to work a variety of lower-body muscles, while McLaughlin issued perhaps the most important tip for proper elliptical form: "No bouncing. Your upper body should be almost totally still."

Most of us ellipticizers (we know who we are) tend to push our entire bodies up with each leg thrust and then allow gravity to sink us into the next one. Aside from cheating your legs out of some of the work, that bounce makes it almost impossible to hold your form intact. This puts knees, lower back and hips at risk of strain.

I followed McLaughlin's directions, and two things happened: My quads sent a flurry of exclamation points up to my brain ("Dude! What's with the Ironman training?") and the calories-per-minute readout on the Precor jumped from around nine (when I was bouncing) to 13.5.

McLaughlin showed me how to use the segment time function -- for example, cranking away in a squat position for two 90-second segments -- while he slyly boosted resistance on the Precor.

Eight minutes in, I am panting hard ("How . . . many . . . clients . . . collapse . . . doing . . . this?") and starting to drip sweat. My heart rate hits 80 percent of maximum.

"Stand up and get your strides-per-minute up around 160," McLaughlin says. If I was bouncing, he says, there's no way I'd be able to sustain that pace and I'd be burning about 30 percent fewer calories. I intentionally lapse into bad form and, sure enough, my stride count falls off and my caloric burn plummets.

Around minute 15, McLaughlin bumps up the incline and intensity and coaches me into a jog (hands off the support bars and swinging at my sides). This requires me to focus on balance. But by this point, sweat is cascading off my arms (no joke) and my total calorie burn count is zipping upward like a digital clock in overdrive.

By minute 30 I have cooked through 438 calories and can feel the accumulated 5,300 strides (!) in my quads, hamstrings, butt and calf muscles.

While you may not get the same roast-and-boast results without McLaughlin at your elbow, there's certainly a lot here to learn about proper form -- and about the untapped possibilities of even the most uninspiring pieces of gym equipment.

No chat today; back next week.

-- John Briley