There will be some among the 30,000 runners registered for the Shamrock Shuffle Sunday who will bail out because of the wintry forecast.

''We usually have 50 to 70 runners and 10 to 15 walkers every Saturday at 8 a.m. -- rain or shine, year-round,'' Ed Packel said. ''Ten of us ran when it was 12-below. We tend to have good showings.''

The group also has good showings in the Shuffle, especially in the age categories.

Packel is 67 and a founding member of the club. He's also a mathematician who has taught at Lake Forest College for 38 years. Packel has run 17 marathons, and while he hasn't run one in 10 years, he's contemplating running one this year with this daughters.

Lois Gilmore, 78, of Janesville, Wis., is a top-ranked runner nationally in her age group. Laura Kennedy, 51, of Lake Forest, recorded the fastest marathon time in the United States in the 50-54 age group in 2007. Julian Gordon, 73, has run more than 30 marathons and is a prominent chemist at Abbott Labs.

''We do it mostly to stay active,'' Packel said. ''We don't have a lot of control over how competitive we are. You get dealt what you get dealt. Some have had knee operations, and some can't run.

''Some take running very seriously. But it's not a club for competitive runners. We just happen to have some.''

Members of the Lake Forest Lake Bluff Running Club will not be among them.

www.Shamrockshuffle.com is the official website of Bank of America Shamrock Shuffle, where you can get the information on runner, charities, results, volunteers, martketing opportunities, and more.

2009 Shamrock Shuffle will bw hold on Sunday, March 29.