Yes, we've all been told to "sit up straight" -- or suffer the consequences of poor posture. But that's just not a particularly scary warning. So let us explain it in a way that's a little more specific: A bent spine might mean saggy breasts. (For the solution to a saggy and flabby belly, check out the all-new Belly-Melt Diet.)

Did that get your attention?

Here's how it works: When you slouch forward all the time -- like you probably do while working on your computer or driving your car -- your chest muscles actually stiffen, which pulls your shoulders forward into a permanent slump. The result: A look that's unbecoming to your bosom. Worse, hunching forward also puts more stress on your upper spine, which leads to neck, back, and shoulder pain. Did your neck start hurting one day and never stop? It's probably the result of poor posture.
But bad posture doesn't just mean slumped shoulders. When you sit constantly -- as most of us do -- the muscles on the fronts of your hips become short and tight. What's more, your glutes -- or butt muscles -- actually forget how to contract. (After all, with so much chair time, they're not being used for much of anything except padding for your hip bones.) Now, the combination of tight muscles on the front of your hips and weak muscles on your backside causes your pelvis to tilt forward. This pushes your lower abdomen outward, making your belly pooch out -- even if you don't have an ounce of fat.

Worse yet, high heels complete the ugly picture. Your high-fashion shoes not only contribute to your pooch, but again, leave you less perky up top as well, according to Rachel Cosgrove, C.S.C.S., author of The Female-Body Breakthrough. Don't get defensive! We're not knocking heels; we're just saying they can make your ankle muscles tight. When that happens -- and if often does over time -- leads to tighter muscles all the way up your legs to your lower back. (Think of the old song: "The ankle bone is connected to the knee bone" It's the same way with your muscles.) And a tight lower back causes you to compensate by hunching forward even more, says Rachel. So your sag worsens. Not a pretty sight.

The bottom line: Your body is a chain of inter-related muscles from head to toe. If you have a problem in one area, it's going to cause problems in another. But you can use this simple three-step guide to slouch proof your posture. Start today -- and you'll begin to look better instantly. (Are you more concerned about the dimply fat on the back of your legs? Then find out How One Celebrity Erased Her Cellulite.)

1. Always sit as tall as you can. Sure, it sounds obvious, but remind yourself every few minutes, whether you're at your desk or in your car. You'll be surprised at how much you tend to slump when you're not thinking about it. Then use these simple cues to set yourself straight.

*Pull your shoulders down and back. Simply imagine that you’re trying to create as much space between your ears and shoulders as you can, and try to hold that position.
*Pretend there's a string attached from your chest to the ceiling, pulling your chest up at all times.
*Brace your abs -- as if you were about to be punched in your gut -- but breathe normally. It’ll seem hard at first, but keep practicing, and it'll become second nature. A bonus: It’ll also help fight lower back pain. (Speaking of pain, check out the Surprising Cure for PMS.)

2. Do an exercise called the hip raise daily. This strengthen your glutes and teaches them how to contract again -- which helps allow your pelvis to move back in its natural alignment. Here’s how to do it: Lie on your back on the floor with your knees bent and your feet flat on the floor. Place your arms out to your sides. That’s the starting position. Now squeeze your glutes and raise your hips so your body forms a straight line from you shoulders to your knees. Pause for five seconds, then lower body back to the starting position. Do two to three sets of 12 repetitions every day.

3. Stretch your chest. This helps loosen your chest muscles, which become short and tighten when you slump. Try a simple doorway stretch: Place your arm against a door frame in the high-five position -- your palm facing forward and your elbow bent 90 degrees. Now step through the doorway until you feel the stretch in your chest and the front of your shoulder. Hold for 30 seconds, then repeat with your other arm. That's one set; do a total of 4 daily.

Popular Stories On ThePostGame:
-- 5 Awesome Arm Curls You've Never Tried
-- The Truth About Swiss Balls
-- The World's Coolest At-Home Workout
-- Coregasm Phenomenon Is Confirmed By New Scientific Study