George Hagenauer, who has been under a lot of stress, is meditating.

Laura Calandrino, not a fan of regular exercise, is power walking.

The Madison-area residents are among 150 people in a UW-Madison study asking if meditation or exercise can ward off colds and the flu.

The research is especially relevant this fall as swine flu levels have soared before enough vaccine against the H1N1 virus is available, leaving millions of Americans wondering how to stay healthy. The seasonal flu vaccine also is in short supply.

Scientists know meditation reduces stress and exercise can prevent chronic diseases. But they don't know if either activity makes the immune system better able to fight respiratory infections, said Dr. Bruce Barrett, a UW Health family physician heading up the research.

The study, which started last month, features eight weekly classes in meditation or exercise. Participants are asked to do the activities 45 minutes a day until May.

"We're seeing if we can influence the immune system to protect against cold and flu," Barrett said.

A third of the participants, serving as a control group, aren't doing either activity. But they, like the others, will receive seasonal flu shots but not swine flu shots, undergo blood tests, fill out surveys and get nasal swabs if they develop a cold or the flu.

The idea is to see if meditation or exercise prevents the diseases or makes them milder or shorter. Researchers will analyze the blood tests and nasal swabs to identify viral strains and see if meditation or exercise boosts the immune system's response to the flu shot.

The study is funded by a $1.2 million grant from the National Center for Complementary and Alternative Medicine, part of the National Institutes of Health. Participants are older than 50, the age group that generally develops the most complications from the flu.

The study is Barrett's latest effort to better understand ways to control respiratory diseases.

His previous research found that patients who rate their doctors highly had less severe colds than those who give their doctors lower marks - a sign that physician empathy can be medically powerful. Results are pending for a related study of whether echinacea, an herb from the coneflower plant, can curb colds.

There is little evidence to support most cold remedies, such as decongestants, antihistamines and zinc lozenges, Barrett said. Most doctors agree those and other common remedies don't do much to make colds go away quicker, according to a survey of doctors Barrett conducted two years ago.

The drugs Tamiflu and Relenza are thought to lessen the severity and duration of the flu, but only if given shortly after symptoms arise, Barrett said.

The mindfulness meditation used in the new study is patterned after a technique by Massachusetts-based instructor John Kabat-Zinn. It focuses on paying attention to the senses. The UW Health meditation classes include some yoga.

The exercise classes feature stretching and aerobic activity, using machines such as treadmills and stationary bicycles.

Calandrino, 66, didn't exercise before beyond short walks with her dog, a West Highland white terrier. At the first exercise class, she was intimidated by the machines, she said.

But "now I just go in and press the buttons, and I'm on my way," said the retired property manager from Fitchburg. "I look forward to exercising."

Hagenauer, 59, of the town of Springdale, said he has been stressed recently by job cutbacks and the death of his mother. He is data manager for Community Coordinated Child Care Inc., or 4-C, a Madison-based child care advocacy group.

"When I'm really stressed, I tend to get sick," he said.

Meditation has given him more energy and helped him sleep better, he said.

"I'm seeing a lot of benefits already," he said. "Not getting a cold or the flu would almost be secondary."