A 37-year-old breast cancer survivor from Colorado made history Tuesday as the first person to swim the English Channel four times in a row.
"I just can't believe we did it," Sarah Thomas told the BBC when she came ashore in Dover, England. "I'm really just pretty numb."
"There was a lot of people on the beach to meet me and wish me well and it was really nice of them, but I feel just mostly stunned," she said. "I'm pretty tired right now."
Thomas spent around 54 hours in the water swimming from England to France, back to England, back to France and, finally, back to England.
In all, Thomas covered around 130 miles, according to the BBC.
(MORE: I breast pumped while crushing a record and becoming the 1st woman to win a 268-mile race)She quickly received congratulations from fellow ultra swimmer Lewis Pugh, who called Thomas a "super-human."
Thomas was diagnosed with breast cancer last November, she told the Financial Times prior to her record-breaking swim. At the time, her doctors doubted that she "would ever return to peak form."
She continued to swim during chemotherapy, but had to put swimming on hold when she underwent radiation.
"It was too painful to swim through my burns," she told the Financial Times. "I blistered and was told it wasn’t safe to swim because of the risk of infection."
(MORE: Surfer rides mesmerizing 68-foot wave, sets world record for largest wave rode by a woman)She got back in the water after radiation and spent the last week in Dover awaiting perfect conditions for her swim, according to the Financial Times.
Thomas wore only a swimsuit, cap and goggles for her swim, during which she was stung by a jellyfish.
She celebrated after coming ashore with champagne and M&Ms.