Multitasking: trying to do two things at once? You may accomplish nothing.

While talking on her cell phone, Lori Tripoli of Bedford, New York, attempted to get organized. She sorted through a stack of paid bills that needed stamps and began tossing junk mail in the trash. Then, with the phone still stuck to her ear, she took out the garbage and congratulated herself on her ability to do so many things at once. It wasn't until an hour later that Tripoli discovered she'd thrown away her newly paid bills. That error earned her an afternoon of dumpster diving out in her condo's parking lot. Luckily no one saw her. "I'm a master multitasker," she explains. "I guess I just shouldn't expect that tasks will be done properly."

Although we consider multitasking to be a fairly modern concept, the idea has been with us for more than a century. During the Civil War, General George McClellan was known for dictating three letters at once to three different secretaries. Later all three letters had to be rewritten--every time--according to a famous Civil War historian, Bruce Catton.

We've all witnessed people who carry on cell-phone conversations as they drive, often weaving perilously dose to other cars, as they become absorbed in conversation. Or they're driving slowly and erratically while concentrating on the phone call. Or they're speeding along and not focusing on the phone conversation at all, which may be about an important business deal.

Employers often list "the ability to multitask" as an important job requirement. But is multitasking really such a positive skill? And, even more important, how does it affect your physical and mental well-being?

Health Under Attack

It's been shown that people suffer memory loss when they multitask. Our mind is like a file cabinet, and it is constantly being bombarded with information and tasks--whether we like it or not. When we multitask, we can't fully concentrate on any of the included tasks and our work suffers because of it, says Kiki Weingarten, a life and career coach in New York City.

"Inability to concentrate on many tasks at once leads to problems with our attention span as mental fatigue sets in," reports Patricia Farrell, Ph.D., a clinical psychologist in Englewood Cliffs, New Jersey. "The longer and more intense the stress, the more likely it will result in some type of mental or physical breakdown."

Farrell offers the following incident to illustrate her point. When the staff of four at one company had to do the work of nine people because of cutbacks, their top-notch salesman developed classic symptoms of panic disorder. The company installed a computer, cell phone, and fax machine in his company car, and he quickly found himself constantly being inundated with tasks. The final straw came when he was asked to pick up his boss at the airport. The man's anxiety level became so strong he couldn't drive. He was asked to take a temporary disability leave, but for someone in his late 50s, that probably heralded the end of his career.

"Multitasking is akin to juggling three balls while jumping rope and cooking dinner," quips Farrell.

When we attempt to exceed our mental limits, stress rears its ugly head and begins to slowly ravage our immune system--opening the door to any number of diseases and debilitating conditions.

The Long Road

In a 2004 poll commissioned by Scientific American MIND, six out of 10 adults agreed that, despite being busier than ever, they often feel like they are getting less done.

Karen Leland, president of Sterling Consulting Group in Sausalito, California, says when multitasking, each task takes longer to complete because there's never a long enough period of focused energy and attention to be efficient in getting any one item completed. "The brain can switch gears quickly, but that doesn't mean it's at full capacity when it does," she says.

Without the full use of your brain, you can't see all the possibilities, insists Marcia Reynolds, a Master Certified Coach in Phoenix, Arizona. "In truth, there's no such thing as multitasking. The brain can only focus on one thing at a time," she says. If you focus on one thing and complete it and then go to the next thing, you will actually save time.

Feeling Stupid

Since you're rapidly changing focus while multitasking, you're constantly losing sight of whatever you are not doing at that second, says Reynolds.

Farrell adds, "The human mind can only keep track of about seven things in short-term memory and, in order to hold those things there, you need to keep mentally repeating the information." Your brain has to regroup every time you change focus. As a result, whatever you had stored in short-term memory is easily lost, making you appear, or at least feel, stupid.

"It's better to do one thing at a time and do it weil," advises Reynolds. "You can set time limits for each task, but give the task 100 percent of your attention while you're working on it." Otherwise, she says, there's no feeling of completion or satisfaction. You don't feel you can rightfully check that item off your "to-do" list when you've done it haphazardly.

You feel more like a hamster running on a wheel that just keeps going around and around and doesn't make any progress, says Leland.

Break the Addiction

Here are some ideas to help you break your addiction to multitasking and start getting tasks done more effectively:

* Keep your cell phone turned off. Only use it to make outgoing calls.

* Set priorities. Rather than just having a list of to-dos, figure out what time periods during the day you are dedicating to working on a specific item.

* Live in the moment. You'll be happier and more connected. Think about what you taste, feel, touch, and hear right now.

* Keep a journal. Journaling can help ease the stress of being overworked. You have to take time to focus on the writing, and it slows you down. It's OK to talk about how frazzled you feel in the journal.

Multitasking That Actually Works

Pairing some simple tasks that don't require much focus makes sense. For instance, you can easily fold laundry while watching television. Sorting mail and talking with someone works only if you're simply separating magazines from envelopes. But if you're trying to actually read the mail, the conversation becomes difficult because you're tackling two language activities: reading and listening.

Farrell advises, "Find your limits and stick to them. If others seem able to do more than you, they probably aren't doing any of it well."

Remember, life isn't a contest to see who can drop into the grave the fastest. Guard your mental and physical health by slowing down to a reasonable pace. Concentrate on the task at hand, and do it well before moving on. More isn't always better.

Heather Larson lives in Federal Way, Washington, and works as an elementary school library assistant.