Listen in as Katherine is castaway at 11:15am on Sunday 26 February.
With one gold and four silvers under her belt – attained over five consecutive Olympics – Grainger retired from the sport after narrowly missing out on gold in Brazil last year.
During an appearance on BBC Radio 4’s Desert Island Discs, host Kirsty Young asked her what is next, to which Grainger revealed she has accepted she “won’t go back and do any more in a boat. “But with that comes liberation and comes excitement and I feel like I am 16 again when I don’t know what to do with my life but I want to do something,” Grainger said.
“I am excited, and nervous and slightly daunted and terrified at the same time as being – you know, just looking forward to it. I just don’t know what the answer is yet though.”
With a rowing career spanning more than two decades, and six world championship titles to her name, Grainger also said she doesn’t have a very successful personal life.
“I suppose I really have devoted myself in probably every way to my sport for the last 20 years,” she added.
“I have had a personal life running alongside it occasionally, but not very successfully. So maybe that is the next area I can move into now.”
During the show she chose tracks including Tina Turner’s Proud Mary and The Whole Of The Moon by The Waterboys, and opted for an archive of the Sunday papers as her luxury item.
She was also quizzed on how she felt to be cheated out of the triumphant moment of winning gold at the 2006 World Championships, by a Russian crew, who later fell foul of a drugs test.
Racing a quadruple scull as reigning champions in front of home crowds at Dorney Lake, Eton, they were beaten into second place, but were later restored as the winners.
Grainger admitted that the initial defeat had a big impact on her and the rest of the crew, but when questioned on whether she smelt a rat, said “not at the time”.
“I think that is not your first thought, your first thought is not ‘oh they must have cheated to have beaten us’ – it was what did we do wrong? We weren’t good enough.
“That is hard to deal with, because we went into a very dark patch of the winter, the four of us in the boat, all trying to see where we had fallen short and why we weren’t good enough, and why we had failed and why we had disappointed.
“It felt like we had disappointed everyone. It took about five months for the news to come out that there was a positive test and they were going to be stripped of their medals.
“And it was just the strangest of feelings because suddenly someone just tells you in the corner of a gym, ‘you are now world champions’, nobody got to see the moment.
“No-one who travelled or paid or anything else got to see us, no-one got to hear the national anthem, there’s also incredible anger that this Russian team had basically brought our sport into disrepute and ruined that moment.
“You just don’t get it back. We got the medal back, but it doesn’t replace anything else.”