Two sisters competing in Race Across the World have said taking part in the tough contest has strengthened their sisterly bond.

Elizabeth and Letitia, from West Sussex, are racing four other teams from China to India in the fifth series of the reality show, which launched on BBC1 on Wednesday.

"Doing it like this is something unexpected, unimaginable, and a once in a lifetime opportunity," Elizabeth told BBC Radio Sussex.

"It was a different way of trying to bond with a sibling, for sure," added the 33-year-old.

Letitia, 26, admitted that they "didn't really take it so seriously" when they applied to take part in the programme, but were soon wondering if they were capable of completing the race.

"We watched it before and I thought 'we can do that, we like to travel'," added Elizabeth.

"But actually doing it and being together 24/7, trying to make decisions together, is a different story."

The contest sees the teams travel more than 8,700 miles (14,000km), starting from the Great Wall of China and traversing China, Nepal, and India without flights or smartphones.

Contestants can only spend the cash equivalent of an airfare between the start and finish points, but the winners take home a £20,000 prize.

"Every day we were surprising ourselves, just being put in situations where you had to make difficult decisions," said Letitia.

She added that, although the pair are "very different", they were able to use this to their benefit in the race.

"We complemented each other along the way," she said.

"But sometimes, while we were going along, some of the differences did bring some conflict that we had to deal with."