LA PALMA, Calif. -- Getting in shape, including losing weight, is by far the most popular New Year's resolution across the United States. Shortly after the excesses of the holidays, many Americans will trek to the gym to shed pounds -- but will add back pain instead.

"Good posture allows for muscular and skeletal balance, protecting the body against injury while exercising," says Betsy Annesser, PT, DPT, medical liaison for Relax The Back. "If you're practicing poor posture in your daily activities -- you're likely to carry that same posture into your exercise routine. The result is often more than you've bargained for -- an episode of back pain that derails all your best intentions."

Here's a checklist to help you avoid back pain while exercising:

--Check your posture. Pull your shoulders back and keep your head erect. Your head weighs 8 to 12 pounds. You strain your upper back muscles whenever you allow it to hang forward.

--Stop slouching. Look for chairs featuring lumbar support and a counter seat pan. Long-term slouching takes its toll on your spine. When supportive muscles weaken, you're vulnerable to injury during exercise. Consider chairs with ergonomic features, such as Zero Gravity chairs, which maintain the neutral posture of your spine even while reclining.

--Stand tall. The taller you stand, the straighter your spine. Your ears, shoulders, hips, knees and ankles should form a straight vertical line.

--Strengthen your core muscles. These vital muscles support your spine. An exercise ball is an excellent -- and safe -- in-home tool for increasing core muscle tone.

--Start slow and be consistent. Poor posture doesn't happen overnight -- correcting it doesn't either. When you start a new exercise program, don't try to do everything at once. Start with fewer repetitions and see how your body responds.