A woman who overcame cancer just last year has become the first person to swim the English Channel four times without stopping, as scientists say her gender could be key to her success.

Sarah Thomas swam for 54 hours - from England to France, to England, to France and back to England, fighting against strong currents, salt water in her throat and jelly fish stings on her face.

The 37-year-old American completed the epic challenge at 6.30am on Tuesday.

Instead of the 80 miles it should have been, Ms Thomas covered nearly 130 miles after tidal pulls took her off course.

She celebrated with champagne and a pack of M&Ms on the beach in Dover.