Olympic gold medallist Helen Glover says the key to a successful rowing pairing is knowing each partner is as committed as the other.
Glover, who partners Heather Stanning, tells The Clare Balding Show: "It's total trust, it's commitment. Halfway through a race, [Heather] needs to know I'm absolutely committed and hurting as much as she is. Otherwise you're going to stop pushing."
Glover and Stanning won gold at the 2012 London Olympics in the coxless pairs.
Watch The Clare Balding Show on Friday 5 June at 2200 on BBC Two and the BBC Sport website.