U.S. endurance swimmer Diana Nyad's completed a Havana to Key West swim on her fifth attempt Monday, 35 years after her first try.

The 64-year-old stepped ashore in Key West just before 2 p.m. EDT, about 53 hours after she began her swim in Havana on Saturday. Onlookers surrounded her in the water, taking pictures and cheering her on as stepped onto the sand. Once on the beach, she was put on a stretcher and received medical treatment, including an IV. Her lips were swollen and she spoke to those surrounding her.

"I have three messages," she told the crowd. "One is, we should never, ever give up. Two is, you're never too old to chase your dreams. Three is, it looks like a solitary sport but it's a team."

Nyad's journey began Saturday morning when she jumped from the seawall of the Hemingway Marina into the warm waters off Havana. She has been swimming the Florida Strait ever since, stopping from time to time for nourishment.

Nyad tried to same swim in August 2012 and was not successful. She set off on Aug. 18 - marking her fourth attempt - but was pulled from the waters on Aug, 21. Her support crew pulled her from the water after deciding that the risks were too high in the open waters, and they later told Good Morning America hat Nyad suffered severe sunburn, a strained muscle and could barely walk. Her lips and tongue were also reported to have swollen greatly because of the ocean's salt water.

Nyad become the first person to swim from Cuba to Florida without a shark cage. She tried to do so three times in 2011 and 2012, with her first attempt being in 1978, according to CBS.

Nyad's official Twitter page stated on Monday that the athlete "sounds strong, grateful, funny & fully enamored with life. More & more in awe of this #XtremeDream."