By Llee Sivitz
Enquirer contributor

Embarking on an exercise program is one thing. Sticking to it takes something else. To maintain a habit, according to the U.S. Department of Health and Human Services publication "Promoting Physical Activity," you need to perform the desired behavior "consistently for six months or more without faltering."

Sound like an insurmountable task?

We asked Central Parkway YMCA executive director and personal trainer Joel Aschendorf and Nutrition Council executive director Lauren Niemes for help.

"It has to be something you enjoy ... and it has to produce the desired results," says Aschendorf. "Some people use competition (training for a race) to put a long-term goal out there. They use their short-term activity to produce that long-term result, either a behavior change or some accomplishment."

Make the time

To get started, first determine how much free time you have. Aschendorf says most people say they don't have time to exercise. "But successful exercisers have only 24 hours in a day, the same as you and me. It's what they decide to do with their time that makes the difference."

Consider skipping a TV program. "There's thirty minutes right there," Aschendorf says.

Make sure your exercise regimen is progressive - taking baby steps - toward your fitness goal. Large goals (like losing 50 pounds) are too hard to obtain right away. It's better to focus on short-term goals (i.e., sleeping better, having more energy, feeling better) and to celebrate those little successes.

Accountability is key. Aschendorf says having someone meet you at the fitness center, whether a trainer or a workout partner, creates a social connection. You show up because someone is counting on you to be there.

Try not to change more than one behavior at a time. A change in behavior actually creates "functional" stress, he says, and changing two behaviors at once can be too much.

"Diet and exercise are very difficult to continue together. I would do only one or the other (at first). Starting smoking cessation and exercise at the same time is also very difficult."

The first three to four weeks are the most challenging time in any regimen; it's when you face your real barriers to exercise and learn the strategies to overcome them. "You are incorporating a new thing in your life and there are many adjustments to be made," says Aschendorf.

There is light, though. The feeling of exhaustion you experience the first few times you exercise eventually turns into a feeling of being energized and elated; you'll begin looking forward to your next workout.

That "looking forward" feeling can be attributed to "endorphins," hormones produced by the body in response to exercise, especially cardiovascular. Endorphins are a natural pain killer.

"All those aches and pains go away," Aschendorf says. "You feel relaxed after exercise."

Don't be alone

Feeling overwhelmed? A support group can help, Niemes says.

"Whether it's within your work site, your gym or your family, developing groups of people who support your goals is critical to maintaining healthy behavior and making it a real part of your life. That doesn't mean you can't still be friends with your slugs."

Says Aschendorf: "Behavior change involves ... an active decision on the person's part to say 'I'm going to stop doing this and start doing this.' "