James Cracknell has said he is worried he will let himself “off the leash” and appear too competitive during Strictly Come Dancing.
The double-Olympic gold medallist rower is among a clutch of sportspeople to have signed up for the BBC One show this year.
Former England number one David James, former Arsenal right-back Alex Scott and Paralympic table tennis player Will Bayley will all make their Strictly debuts on Saturday night.
Cracknell, 47, said he did not expect them to get competitive.
He told the PA news agency: “It’s different with your own sport because you know what you’re doing and can cope with the pressure.
“Whereas this is about something you can’t do – so you can’t take it in the same way. It’s not that fun for the show if you look like you’re not enjoying it.
“You still have that fear of letting yourself of the leash.
“You don’t want to look stupid or rival-ish against the people you’re racing against, so it’s that sort of mindset that if you don’t care what you look like you improve really quickly.”
He added: “If you hold back, that’s the biggest hurdle.
“Being in sport will mean that you’ll get the best out of yourself on a Saturday night.”
Cracknell joked that he hoped his professional partner was willing to cut him some slack in the practice studio.
He said: “I’m relying on them to be competitive and for me to be just led by the hand.
“We’re all varying degrees of good to shit, not amazing to rubbish.”
Cracknell won rowing gold medals at the 2000 and 2004 Olympics, and earlier this year became the oldest university Boat Race winner.
He signed up after splitting from his wife, television presenter Beverley Turner.
Turner, 45, was previously reported to have barred him from putting on his dancing shoes because of the so-called Strictly curse.
Strictly Come Dancing returns to BBC One on Saturday September 7 at 7.10pm.