Do you need to increase your network of close friends? Do you need to enlarge your social world to help you feel less lonely?

Maybe you're a stay-at-home mom who feels lonely without adults around during the day. Or, maybe you're newly retired and missing your friends at work.

If so, think about getting involved in some sort of exercise program. It's easy to meet new people this way.

Sign up for a formal exercise group that meets two or three times a week. We promise that you'll get to know quite a few people within a couple of weeks.

Building close relationships isn't usually quick or easy for any of us. Keeping those relationships healthy and working for us can be tricky as well. Friends and family can move, divorce, pass away, change jobs, or become ill.

When changes happen, any of us can feel a huge empty space in our network. An exercise program gives you a time, place, and excuse to get out of your rut and talk with a lot of nice people.

The three of us have been writing this column for nine years. We get letters and emails from people all over the country. They contact us either by sending mail to one of our publishers or from our website.

The biggest topic of complaint we hear is this: "I feel lonely."

Wouldn't you think that domestic violence, problems at work, or some other issue would prompt people to contact us?

Nope. Their foremost topic of concern is loneliness.

One man wrote to us recently: "I'm lonely because my wife is ill." He is visiting her in the hospital after she fell down a flight of stairs at work.

"When I go home at night, I feel this crushing alone thing that I can't shake," he wrote. "But, I feel guilty for feeling so alone. She's the one who has a crushed pelvis."

You don't have to be single to be lonely. Neither do you have to be old or shy. You can be a well-dressed, well-educated, upper-income working person and still feel lonely.

"The good thing about attending an exercise class is that it's informal in so many ways," says a physical trainer we'll call Ed. "Civic groups or church are good places to connect with others, but in an exercise class, you can laugh and act a little open and crazy. That's why it's so good for the spirit."

Ed points out that people come to exercise classes for different reasons. But, he emphasizes, "In an exercise class, you automatically have many things in common with others right off the bat. Everybody is struggling to get to the same place on time. And wanting to get fit and having personal goals related to that ensures you have something to talk about with everybody in the class."

"I was bored out of my mind," says Trina, woman who recently lost her job. "When I quit work, I lost my network of friends, business associates, and my lunch-hour social life," she points out.

But, says Trina, when she works out at the YMCA two days each week, she connects with three women who are informally coaching her and encouraging her to keep plugging away on her job search.

"Sauna time at the Y is really good for laughter and bonding," Trina insists. "It loosens me up at a time when I'm so worried and on edge."

Depression, which often accompanies loneliness, can be reversed to a notable degree by exercise. Aerobics, yoga, or working out on machines gets the body revved up and producing healthy hormones. This helps counteract that "blah" feeling.

"My only child just left for college this past fall," says Gayle, a single mother in New York City. "I got laid off from work temporarily during our office renovation. I was just moping around the apartment. My mom, who is pretty sound financially, sent me some money. She insisted I join a gym using part of her gift."

Gayle met three professional women at the gym who now join her for lunch occasionally. She also lost 10 pounds and got a job offer from a man in her yoga class.

Gaining friendships and support in an exercise class can lead to dating or mating. However, we don't recommend that you join an exercise class letting others know -- or guess -- your real motive.

Keep your goal to date or mate very, very low key. This works better in the long run.

"When people come to flirt and connect with the opposite sex, it can make others in the class very uncomfortable," says a gym owner we'll call Bob. "It's okay to talk and connect discretely with the opposite sex, but I have had some really emotionally hungry people coming in. They laugh too much, talk too much, and generally disrupt a class. That's not cool."

Bob continues, "One man in our water aerobics class took off his wedding ring during our pool workouts, so he wouldn't lose the ring. A really pushy woman started hugging and touching Bob. Bob's wife almost drowned this touchy feely woman when she saw what was transpiring!"

Bob goes on to add, "I'm not saying that exercise class isn't for connecting, I'm just saying that when you keep it very low-key, it works better for everyone involved. Don't be overt in trying to meet someone for dating in an exercise class. Let it happen smoothly and naturally."