When Mack Gold turned 100 years old, he celebrated by doing a few push-ups in the middle of the living room. That was three years ago.
Now 103, the recipient of a Purple Heart in World War II is no longer up to an all-out aerobic workout, but he keeps a positive attitude as he rolls toward his goal of becoming the oldest person in the U.S.
"If it works out, fine," said Gold. "If not, I'm still proud of myself."
The competition is fierce. As the nation marks May as Older Americans Month, there are more than 72,000 centenarians in the U.S., according to the Census Bureau. As many as 4,000 are residents of Florida.
The century club is growing by the day. Indeed, Americans over 100 make up the second fastest-growing segment of the population. The only group growing more rapidly: supercentenarians, those at least 110 years old.
The world's oldest person, at 114, is believed to be Bessie Cooper, of Monroe, Ga.
At 102, Ruth Greenstein of Delray Beach said she does not know how long she will be around, but she plans to stay busy designing and making jewelry and playing bingo.
At Heritage Park East, an assisted living facility, Greenstein also loves to talk, especially of the trip she made to the U.S. from her native Poland as an unaccompanied 14-year-old.
"She is a remarkable woman," said Greenstein's daughter, Fran Weinberg, 78, of Boynton Beach. "She loves to be with people, she reads a little and tries to keep up."
Reaching 100 is not the oddity it once was. Hallmark has been printing milestone "Happy 100th Birthday" cards since 1986. A cake with 100 candles no longer guarantees a photo in the local newspaper.
Nor does reaching an advanced age necessarily mean disability or loss of mental acuity. It doesn't always even mean retirement: In Wichita, Kan., U.S. District Judge Wesley Brown remains on the federal bench at 103.
Among newcomers to South Florida's century community is Vincent Giacalone of Hallandale Beach, who marked his 100th birthday on Feb. 25. Like Gold, Giacalone is a veteran of World War II, among the oldest of those drafted into the Army after the U.S. entered the conflict in 1941.
Giacalone — called Jimmy — dances, cooks spaghetti and other dishes from his native Italy and goes to Gulfstream Park every weekend to play the ponies.
"I take care of myself," said Giacalone, a former barber. "What I don't do is sit in front of the television and sleep."
Gerontologists and other researchers have come up with many theories to explain increasing longevity, including improved medical science, social engagement, physical exercise, the ability to handle stress and good luck.
In their book "The Longevity Project," Howard S. Friedman and Leslie R. Martin called on eight decades of research to conclude that "the best childhood personality predictor of longevity was conscientiousness, the qualities of a prudent, persistent, well-organized person, like a scientist-professor — somewhat obsessive and not at all carefree."
Many researchers think genetics are key; if your parents lived long lives, so might you.
"We age at different rates, and that is a consequence of genetic make-up, along with our interaction with the environment," said Nir Barzilai, director of the centenarian study at Albert Einstein College of Medicine of Yeshiva University, in New York City.
"Ask yourself if you know someone in their 60s who looks like they are in their 50s. Most people do, and that is mindblowing to me. It shows that people intuitively understand that we age at different rates."
Giacalone and Gold both come from long-lived families, and both still live full and active lives.
Giacalone came to the U.S. with his parents when he was 10. Drafted in 1942, he served with the Army's 116th General Hospital Corps in Germany.
After the war, he learned to cut hair from a cousin, and for many years had the barber shop concession at Belmont and Saratoga race tracks. There he trimmed the locks of movie stars and mobsters, and has pictures of himself with some of the celebrities he's scissored, including jockeys Eddie Arcaro and Willie Shoemaker.
A former competitive dancer at Roseland Ballroom, Giacalone has been married twice but has no children. His parents lived into their 80s, and one of his two sisters survives, at 96, in New York.
Judith Leviton, Giacalone's caregiver for the past four years, describes Jimmy as "a very independent man, with a magnetic personality." Together they attend exercise classes and socialize at the Jewish Community Center in Aventura.
Gold, who recently moved to The Bridge, an assisted living facility, was born in 1908 in Palestine. He came to New York with his family when he was a child and grew up in Manhattan. He served with the 36th Armored Infantry Regiment during World War II, and was wounded in the leg by shrapnel.
Discharged, he returned to New York he got into the hardware business. He married and had one child, a daughter, Carol, 64.
"He does crossword puzzles, never takes even an aspirin, and knows everything that's going on," said Shirley Skokan, 91, Gold's companion for the last 16 years. He has a brother who, at age 95, still drives.
Gold summed up his philosophy this way: "Work hard, live clean, exercise and never charge anything."
Greenstein left Europe for New York in 1922. When a relative she was to travel with became sick, Greenstein spotted a couple with several young children and made a deal: let me join your family group and I'll watch the kids.
Left behind in Europe were Greenstein's parents and four sisters. Prior to World War II, two of the sisters fled Poland for what would become Israel. But her parents and two younger sisters were killed by the Nazis.
In New York, Greenstein married and had two daughters. She was active in groups supporting the state of Israel and sewed uniforms for U.S. soldiers. Her husband, Ben, a plumber, died about 15 years ago.
Until recently Greenstein volunteered with a local organization that makes hats for cancer victims. She can still thread a needle.
From a meeting with the National Council of Senior Citizens, President John F. Kennedy in 1963 designated May as Senior Citizens Month, encouraging the nation to celebrate those 65 and older. In 1980, President Jimmy Carter's proclamation changed the name to Older Americans Month.
"Having lived through many of our nation's most challenging times, older Americans have shaped the story of America and secured the promise of our future," said President Barack Obama in a proclamation issued Friday. "We are privileged to recognize these treasured citizens during Older Americans Month, and honor both the impact they have made and their accomplishments yet to come."
According to census figures, there were 39.6 million people 65 and older in the United States on July 1, 2009. This age group accounted for 13 percent of the total population.
For the vast Baby Boom generation now just entering the traditional retirement years, centenarians should be role models, according to Lynn Peters Adler, who runs the National Centenarian Awareness Project.
"Older people aren't just sitting around," said Adler, of Phoenix. "I have a friend here in Arizona who is 103 and she just renewed her driver's license. I think centenarians themselves have a greater sense of their own potential."Copyright © 2015, CT Now