BAY SHORE, Long Island — A woman from Long Island is celebrating her 100th birthday, but even more impressive than that milestone… she can do things that many 20-year-olds can’t manage.

A typical aerobics fitness class is anything but typical for Geraldine “Jerry” Leo.

“April 11th is my 100th birthday,” she said.

It’s not just her high tempo, pristine hearing and hand-eye and foot coordination. At the Great South Bay YMCA in Bay Shore, Long Island, it’s the ability of this great grandmother to do a five-minute plank.

The class quit at two minutes, but not Leo. She comfortably holds steady until three.

Her impressive stamina and form were carried out just three days before her 100th birthday.

“She’s a strong woman,” said Great South Bay YMCA Health and Wellness Director Despina Tenedorio.

Group fitness instructor Elizabeth Grant says Leo’s plank is “really unbelievable.”

“She definitely puts some of the class to shame, including me,” said Leo’s friend Marion Saturno.

“Her form is beautiful and she can teach people how to do it the right way,” Grant said.

Which is exactly what she did with ABC New York affiliate WABC’s reporter Chantee Lans.

“The Y has been a big part of my life,” Leo said.

It started because of her late husband Dominick, who encouraged them to join the YMCA when it opened in 1991.

“Jerry is an inspiration to everyone who meets her,” Grant said.

“I tell her all the time. She’s my hero,” Saturno said.

The centenarian shared her secret to longevity.

“Be consistent, be positive, and keep moving in whatever you do. That’s very important,” Leo said.

It’s not just aerobics. Leo also takes a weightlifting class on Fridays, but this week for her birthday, both the YMCA and the mayor of Babylon are celebrating her.