Group members move slowly, gracefully in unison to inaudible music. Visitors to local parks who see the sessions wonder what the participants are doing. Now they can be part of the activity free.
The last Saturday of April was chosen in 1999 to promote the related disciplines of tai chi and qigong (pronounced chi kung). Novices and veterans are invited to join in the series of free classes and exhibitions taking place around the world. Starting at 10 a.m. April 27 this year, tens of thousands of people in hundreds of cities in 70 nations will take part in what's become an annual event.
Each year, World Tai Chi Day kicks off in New Zealand, then moves through remaining time zones through Asia, Africa, Europe, South American and North America.
New York's Central Park is the site of a giant World Tai Chi Day get-together, as are Golden Gate Park in San Francisco and Balboa Park in San Diego.
In Mt. Lebanon, David Clippinger and his Still Mountain Tai Chi School have hosted World Tai Chi Day since 2003,usually at Bird Park.
"The sessions are perfect for novices as well as for those who've been doing it a long time," Mr. Clippinger said. "People can come and go as they please. The idea is to give them a taste of tai chi to let them see what it's like." Classes are offered at a number of places in the region for those who develop an interest.
World Tai Chi Day is free and is held rain or shine. Over the years, he's had a many as 300 attend.
"It's weather dependent," he said.
Participants are encouraged to wear comfortable clothes and sneakers.
"Tai chi is actually an ancient martial art, although not many people practice this aspect of it any more," Mr. Clippinger said. The most authentic form of tai chi has three components -- health, meditation and martial arts, he said. Like a stool with three legs, if one of the "legs" is removed, the stool collapses.
Mr. Clippinger said tai chi and qigong each use breathing techniques, relaxed muscles and slow movement. Qigong, however, tends to be more stationary and medically focused, though both have proven health benefits.
On his website, stillmountaintaichi.com, Mr. Clippinger, who has a doctorate, says the World Health Organization has recognized that tai chi and qigong, alongside other traditional Chinese medicine practices such as acupuncture, are effective treatments for many disorders.
The American Arthritis Foundation promotes tai chi, and the Mayo Clinic recommends it for all of its employees, Mr. Clippinger said. He teaches classes at Highmark and UPMC sites for employees.
Mr. Clippinger said that, in China, tai chi is recognized as something people do after they retire. In the Western World, however, people start earlier while still in their 50s, when health issues are beginning.
"Tai chi is meant to be a lifelong learning experience," he said. "The more you do it, the more you get out of it. One of the big advantages of tai chi is that it can adapt to a variety of fitness levels. But no matter how fit you are or aren't, it can improve your health."
Mr. Clippinger said tai chi is also intended to be fun.
"A lot of people approach exercise as work," he said. "And that's what our goal for World Tai Chi Day is -- to make it fun."
Dave Zuchowski, freelance writer: firstname.lastname@example.org.