Raising money for a good cause was "a walk in the park," for the thousands who showed up in Central Park Sunday for the fourth annual "TGL Classic."

The event raises money for lung cancer research. It was organized by the Thomas G. Labrecque Foundation, and the New York Road Runners Club. Thomas Labrecque — a former chairman of JP Morgan Chase — died of lung cancer.

Participants chose between a 4 mile run or a 1-point-7 mile walk. The race circled the park; beginning and ending at the 72nd Street Transverse.

Some runners say their lives have been effected by the deadly disease.

"One of my very close friends just passed away about six weeks ago of lung cancer; compete surprise: never smoked, a beautiful person," said one runner.

"In fact, my father died of lung cancer at age 54. So we always train and help those causes," added another.

It's estimated that close to 6,000 people took part. Organizers hope to raise over $700,000 for lung cancer research.

Sunday's run also counted as a qualifying race for next year's New York City Marathon.