A friend recently told me a popular phrase making the rounds online. It's been edited slightly for print:

"Ask your doctor if getting off your (rear end) is right for you."

I laughed out loud and thought about the benefits of getting off your duff. Then I asked my doctor. We discussed fitness benefits, chuckling the entire time.

Wouldn't you love to lie down on the job, and kick your butt at the same time? Do unstable training for your core body.

Our middle bodies are typically the first place we lose strength, flexibility and function. Abdominal muscles grow slack and start sagging over our waistbands. Fat backs bulge, spilling out of bras and T-shirts.

Our technology and cushy sitting-on-your-(read end) lifestyles bring the blues and extra body fat over time.

The abdominals consist of three groups of muscles:

The rectus abdominus, which is the front sheath that makes up the "six-pack."

The obliques lie at the sides of your waist.

The transverse abdominus acts like a corset to hold in your internal organs and improve posture.

When it comes to exercise on the Swiss ball, you'll feel muscles that typically go unused. It ups the ante because it activates the arms, legs and hips, which provides additional resistance to target upper and lower abdominal muscle fibers. So, here's one of the most effective exercise routines I use with people, putting a high priority on their core fitness:

Swiss Ball Incline Supine Trunk Curl:

Sit on the ball. Walk your feet forward away from the ball. Allow the buttocks to move down near the floor. Positioning varies the intensity of this exercise. Beginners should start with their bottoms closer to the floor. This lightens the load on the neck and abdominals and creates more work for your quads and gluteals for the purpose of stabilization.

Raise your arms up like a boxer. Make a loose fist facing each shoulder. Feet should be shoulder-width apart with your knees directly over the ankles. Breathe naturally.

Keep your head in line with the spine. Remember to stabilize the pelvis by keeping your hips pressed against the ball. The ball should stay still. Keep your movements slow and deliberate; avoid using momentum.

Pause momentarily at the end of the curl. Exhale as you focus on sliding the ribs toward the hips instead of lifting the upper body. Slowly lower to starting position. It's the quality of the movement that counts, not the number of repetitions.

This exercise actively works the abdominals through a full range of movement. It has an extra challenge because of the recruitment of stabilizing muscles throughout the body that get used.

Get on the ball for more core fitness and get your rear in gear.

Doctor's orders.

D.J. Reese, a personal trainer and fitness instructor, writes on fitness in Players. She can be reached at