ELLEN KEANE was born with one arm much shorter than the other, but says every centimetre counts when she’s in the water.

Now 20, the Dubliner was 13 when she competed at the Beijing Paralympics. She won two bronze medals at the last World Championships and hopes to do at least as well at the World Championships in Glasgow in July to earn a place in Rio next year.

‘For my category, my arm has to be one quarter of my right arm and I am on the borderline. They put me in different categories to race depending on the measurement.

It can be the difference between winning a medal or not – every centimetre has to be so precise,’ she says.

She balances sessions in the pool and the gym with study at the Dublin Institute of Technology.

‘My lecturers probably wonder who is that girl falling asleep all the time,’she says laughing.

‘It’s all about swimming.’

Born without knees or shin-bones, Corkwoman Orla Barry, 25, had both legs amputated aged 11 months. But the Paralympic bronze medallist has never let this hold her back.

‘I just think nothing is too big to get in your way,’ she says. ‘Everyone in Paralympics has had to overcome something to get where we are.

‘If you stick with something, and work hard at it no matter what is in the way, you can overcome anything.’

She throws a 1kg discus, the same as in the Olympics.

Deciding what to do with her prosthetic legs in competition can be tricky. ‘I went through a stage of wearing one and not the other. It’s all trial and error to try to get as much out of your body as you can.

‘You’re trying different things, putting yourself in different positions… all strapped down maybe so your bum doesn’t lift as you throw.’

Orla spends much of her week driving to training in Wexford and Limerick. While she had 96 supporters with her in London, she jokes that not that many will make it all the way to Brazil.