Some 70% of Americans know the feeling: Some time during the workday, the stomach tightens. The heart races. Palms grow damp, breathing becomes shallow.

Job pressures are the No. 2 cause of stress after financial worries, a recent survey shows. And while most of us struggle to manage the stress of a demanding boss or a mounting workload on our own, more employers are trying to help. Efforts include earnest-sounding techniques like 'mindful communication' and 'cognitive behavioral training' as well as office designs featuring leafy, plant-covered walls.

Such stress-busting attempts may have some rolling their eyes, but recent research shows they can actually change the way the brain and body react to stressors. Researchers are using brain imaging and hormone-sampling technology to measure the techniques' physiological impact.

One of the most effective stress-beaters, research shows, is a training program called 'mindfulness-based stress reduction,' developed years ago at the University of Massachusetts Medical School, but adapted in recent years for the office. Numerous studies link training in the technique to increased activity in regions of the brain involved in self-control and the ability to pay attention and process sensory input.

That is, assuming harried employees can find the time for it. The program, which typically involves eight, two-hour weekly sessions, plus a final full-day retreat, teaches meditation techniques like breathing and bringing thoughts back when they wander, says Diana Kamila, a senior teacher at the university's Center for Mindfulness. Participants also learn stretching, yoga and 'body scans' -- noticing their responses to stress, softening their muscles through breathing and tuning in to the feelings and sensations of the moment.

Employees learn to practice periodic 'check-ins' while working, walking, driving or eating. And they are encouraged to blend the techniques into their daily routines, at their desks, in meetings or during talks with colleagues.

At Dow Chemical Co. in Midland, Mich., researchers recently tested a seven-week version of the program, delivered via a one-hour weekly Web conference, workbook and online exercises, for 90 managers, administrators and manufacturing-plant workers. Employees were coached on accepting daily hassles without judgment. If stuck in traffic, for example, they were encouraged to appreciate the sights, sounds and smells around them without stressing out, says Kristin Levanovich, a partner in the Petoskey, Mich., corporate-health research firm, The Aikens Approach, that developed the program.

To reduce the stress of boss interactions, they were also taught 'mindful communication' -- visualizing themselves in the meeting while focusing on breathing, paying attention to what is being said, and asking questions rather than blaming, criticizing or becoming defensive, says Kim Aikens, a physician and lead researcher on the project. Researchers are still measuring the effects on stress and health. Dow Chemical's chief health officer, Catherine Baase, says preliminary results are promising.

Older stress-management programs like teaching employees to close their eyes and count backward from 10, or holding 'self-guided group therapy' sessions to vent 'were naive and didn't work very well,' says Kenneth R. Pelletier, director of the Corporate Health Improvement Program at the University of Arizona College of Medicine.