DAY IN, DAY OUT, people believe they can win their headlong race against time by maintaining an excessively hectic pace. As soon as they wake each morning, the same questions plague their minds: “What do I have to accomplish today? How do I get it all done as quickly as possible?” The term “relaxation” is practically a dirty word.

At some point, such driven people are likely to hit the wall. Their built-up tensions will be unleashed on some unfortunate, unsuspecting person. Or they will find themselves in the hospital with a bleeding ulcer or heart palpitations. At a minimum, they will become less effective thinkers, defeating their very ability to accomplish mental tasks. Constant scrambling and extreme workloads may bring success short term, but the long-term, negative effects are serious.

Even children are feeling pressure to overachieve these days. At a young age, they already exhibit a pronounced tendency toward competitive behavior. In 2003 the Lucile Packard Foundation for Children's Health in Palo Alto, Calif., surveyed parents whose children were nine to 13 years old; 35 percent of respondents said they were moderately or very concerned that their children were under too much stress. More and more boys and girls are pressuring themselves to always be better than their peers in whatever they do. Their lives are overshadowed by a fear that they will not live up to their own goals or the demands of their parents and teachers.

It seems that many adults have lost the ability to simply switch themselves off from time to time—to take a break—and youngsters are not far behind. This is a scary development, because the ability to relax is an important prerequisite for optimal performance on the job and in the classroom—and for a healthy life. Our brains, bodies and personalities are hurt by constant stress. Under this condition, the brain sends ongoing alarm signals in the form of high levels of the stress hormones epinephrine, norepinephrine and cortisol. Their presence raises a background level of anxiety that blocks the processing of information. The antidote is some purposeful downtime.

Go to the Mental Movies

Bosses and teachers, as well as employees and students, must understand that periods of relaxation are not a waste of time. We need breaks to quell stress, lower inhibiting hormone levels, clear out distractions and extend energy reserves. A little relaxation improves attention and concentration. Research by noted psychobiologist Ernest L. Rossi, in private practice in Los Osos, Calif., and others suggests that our bodies benefit most from a 20-minute reprieve about every one and a half to two hours. If we do not allow ourselves this recovery time, our performance will begin to deteriorate, and we will start to feel worn down. The losses may not be immediately evident, but they build up, depleting brain and body and making us agitated, aggressive, hypersensitive or depressed.

Dozing or being lazy for those 20 minutes is not the answer, however, in part because these states dull one's mental edge. Active relaxation relieves stress better yet keeps the mind primed.

The best active relaxation is a short mental vacation. Find a comfortable sitting position and close your eyes. Breathe calmly and regularly. In your mind, picture a particularly relaxing moment. Choose any scene you want, such as a quiet afternoon walk on a beach. During this imagined trip, think of as many sensations as possible—feel the soft sand between your toes, smell the salty air, hear the surf, enjoy the warmth of the sun on your face.

With only a modicum of practice, you will find that these “mental movies” can quickly lead to moments of deep relaxation.

To make your mental movies most effective, when you close your eyes think of a phrase to initiate the exercise each time, such as “I'm now going on vacation.” Then focus all your attention on your breathing. When you begin to breathe in and out, fully expand and contract your lungs: inhale slowly for six seconds, hold the air for three seconds and exhale for six seconds. To help control your breathing, imagine there is a candle in front of you; you are not trying to blow it out but simply to make the flame flicker. Do this exercise a second time and take note of the letting go you begin to feel.

If you can repeat this cycle numerous times, your epinephrine levels will subside and feelings of stress and anxiety should taper off. Then you can really enjoy your mental vacation, whether you are at the beach or on a mountaintop. When you want to end the exercise, be sure to return to your surroundings as gently as possible. Try mildly contracting all your body muscles while slowly opening your eyes.

Younger children may find such guided relaxation too restrictive. Instead of focusing on breathing, it may be easier for them to think of “quiet time.” Renowned Italian educator Maria Montessori discovered that most children love the quiet (which may seem unbelievable to many stressed-out parents) and respond well to the following instruction: “Close your eyes. Be completely quiet. Don't move. Hear the silence and listen to your body.” And if young people find it difficult at first to develop a soothing mental image like a beach, read them a story, and they will readily transport themselves to an imaginary world, which is the real goal.

If a child has great difficulty keeping still and silent, calm background music can provide an ideal bridge. The same applies to adults who have trouble relaxing. Listen to melodic, instrumental music, allowing your thoughts to flow freely. For a short break at the workplace, imagining such music is enough—close your eyes and turn on your mental CD player.