WHY ISN'T MY WORKOUT WORKING?

You work out - a lot - and you've always seen results. So what's with the sudden stall in your weight loss?

Your four-times-a-week fitness routine used to leave you huffing and puffing, sore for days and steadily dropping pounds. But four months later you're barely breaking a sweat, you can't detect the slightest "ouch" in your calves—and worst of all, the scale has been stuck on the same three digits for weeks! So why did your workout stop working?

According to Richard Cotton, an executive wellness coach and former VP of the American Council on Exercise, it's because your exercise routine has become just that—routine. "With repeated, regular exercise, our bodies become very efficient at whatever it is they've been doing—which is a great thing if you're running a marathon and trying to conserve calories—but not if you're on a walk around the block trying to burn them."

So what should you do when you're too good at your workout? Here are some tips:

Pick up (then slow down) the pace.
On your evening walks, instead of breezing past the Smiths' mailbox, zigzagging through the park, and making it back to your front door in 45 minutes flat—like always—try adding intervals. "Pick a point one or two blocks ahead and walk briskly until you reach it, then walk it off until you catch your breath, then repeat," suggests Cotton. The work intervals (or brisk walking) will stimulate the body at a level that it's not accustomed to.

Change your routine. Then change it again.
Have three or four fitness routines, and rotate between them every four to six weeks, suggests Karen Merrill, MS, a personal trainer in Traverse City, Mich. For example, "If Tuesday is typically 'chest and back day' switch it to 'back and biceps day' for a while." (Just be sure your routine includes cardio, strength training and flexibility.)

For a new take on your biceps curl session, try standing on a balance board while you're lifting weights to strengthen your core. And if the treadmill feels like your home away from home, try the rowing or elliptical machine, says Merrill.

Nothing ventured...
"An inexperienced swimmer will exert a lot more energy and burn a lot more calories treading water in a pool than a swimming pro," says Cotton. So find something you don't know how to do—and give it a go! Get into that yoga class you've had your eye on (even if you hide in the back row), or get a trainer to show you how to use some of those gym machines that look oh-so-daunting. But if you really must stick with your regular run, take it outside, on a trail or along the beach. Not only will the difference in terrain jump-start your jog, but getting in touch with nature might be just what the fitness-plateau doctor ordered.

-Michelle Olson, Weight Watchers