"It was a real wall," confirms the swimmer. "The story behind it is I got badly bitten on a training camp in Tenerife, there was bed bugs or something that were eating me which wasn't fun. The bites had swollen and were like massive golf balls underneath my arms. It was really quite tender and I couldn't lift my arms properly, it was agony when I was swimming.
"There was a particular [training] set that my dad [her coach] got me to do of 20x200m backstroke and the times I was hitting weren't very good. In my head I admit I was frustrated because I knew I could swim a lot better, but my technique just wasn't there because I couldn't lift my arms up any higher.
"I thought: 'I just want some other part of my body to hurt so I can focus on that instead of the pain in my arms.' The wall felt quite rough so I decided to punch it to skin the top of my knuckles. I guess I did vent some frustration, but it wasn't solely punching the wall because I was angry. I had thought it through, it was calculated." There is a pause. "I don't have any anger issues," she adds.
Did the plan work? "It did – I went 15 seconds quicker," she says. "There was a little bit of blood so that when I put my hand in the water it stung. As I was swimming I couldn't help but smile a little bit because all I could feel was my hand. It meant I could get back to my normal technique. I think it goes to show the power of the mind, that you can change the psychology of your thinking and push your body to its limits."
This will be Commonwealth and European gold medallist Miley's second Olympic Games after competing in Beijing in 2008. The 22-year-old, who is based in Inverurie, is one of six Scots who are part of the 44-strong Team GB swimming squad, alongside Robbie Renwick, David Carry, Michael Jamieson, Caitlin McClatchey and Craig Benson.
"We have a real camaraderie," she says. "That's one of the things I love about swimming. We all train at opposite ends of the country, but as soon as we get together we gel like we have been training together all of our lives. We support each other. There is a natural team spirit which is awesome. The Scots too, I guess we have that extra special bond. Yes, it's an individual sport, but having that team support helps boost our confidence and morale."
Her father Patrick, a North Sea helicop- ter pilot, former soldier and triathlete who has worked with Olympic gold medallists Ian Thorpe and Brooke Bennett, has coached Miley from day one. He has a skill, she says, for knowing how to get the best from her. She shrugs off the often-posed question as to whether it is difficult having her father as her coach.
"I have never known it any other way. For me it's the norm," she says. "When I was younger, I guess I didn't appreciate how much knowledge and love for the sport he has. It's only as I got older that I've had my eyes opened to that. I have complete trust in him and for that reason it works. A father-daughter relationship is no different to a coach-athlete relationship – you have to build that bridge. You are going to have fights, everyone does in whatever relationship. It's what we do to come round from that which is important. For me, it is a def-inite gut instinct that he is the best person to coach me, so why fix what's not broken?"
Miley will compete in the 200m and 400m individual medley, with her biggest rivals at London 2012 including prodigious American Elizabeth Beisel and Australian triple Olympic gold medallist Stephanie Rice.
"I'm always aware of how many compet-itors there are, it's not just one or two. There are a lot who have suddenly progressed in the 400m individual medley. We all go into this competition as names on a piece of paper. You can't say: 'Oh, these are the two top dogs I need to beat', because someone else might have the swim of their life."
Miley has the opportunity to win one of the first medals of the Olympic Games. The 400m individual medley final will take place around 7.30pm on Saturday evening, only a matter of hours after the men's cycling road race has concluded on the Mall. She is all too aware that if Britain's Mark Cavendish doesn't win his predicted gold in that event, all eyes will turn to the pool in the hope of seeing her get the nation's medal tally rolling.
"Erm, I try not to think about it," she says, with a nervous laugh. "All I can do is focus on what I need to do. I can't control what anyone else does. I might be able to do a two-second PB, but that turns out to only be good enough for fourth. I have set targets and aims, but I can't control what expectations other people might have. I appreciate all the support and will do my damn hardest to make everyone proud, but more importantly I will stick to my race plan and not get too distracted. If it's good enough for a medal on the day, I can't complain."
With her first race on day one, it means forgoing attending the Olympic opening ceremony for an early night – a sacrifice Miley is happy to make. "To train for all those years only to be standing around out in the cold for three hours probably isn't the best preparation right before you race. For me, I'm not fussed. I'm happy to watch the celebrations on TV and then be able to get to bed when I need to."
Miley still trains at Inverurie swimming pool, the same modest 25m long, four- lane facility where she first learned to swim. The contrast with the Olympic Park Aquatics Centre could not be more stark. Yet it was important to her, says Miley, to maintain that link with her roots.
"You could have the best facilities in the world but if you don't have the right coach it won't work," she says. "I wouldn't ever give up being able to train with my dad for a 50m pool. I would always pick my dad hands down."
While dad Patrick is her coach, mum Carmel is "the person that keeps us all sane and the glue that holds us together". "Without her I think we would all have a mental breakdown. I don't know how she does it. She is like Superwoman. She does the cooking, cleaning and keeps us all in check," she says. "I do try to help her out by doing my part with cooking tea and the cleaning side of things. It's nice to have a role model like her to look up to. She def- initely keeps us grounded. If dad and I are talking about swimming too much, she puts her foot down and says: 'No, we need to have some family time.' She certainly plays her part and without her we would definitely crumble."
A self-described "home bod", Miley likes nothing more than a Saturday night on the sofa in front of the telly with her parents and two younger brothers. "It's a nice unit we've got," she said. "We like to spend some time together where swimming isn't involved. What I like to call 'normal' family time."
Her nickname is "Smiley Miley" – does that sum her up? "Yeah, I guess so," she says, not sounding overly enthused. "I don't mind it. I suppose someone could think up a nickname which is a lot worse," she laughs. "I just like being happy. It doesn't take much. A single smile can make all the difference to your day. I do smile a lot."
As for London, Miley is ready. "I guess every athlete's ultimate goal is to win an Olympic medal," she says. "To be able to win one in a home Games I must admit has crossed my mind several times. I have my goals and targets but I am keeping them to myself, only because it puts less pressure on me. To win an Olympic gold would be absolutely awesome, but it's a lot of hard work to get there and no one is going to hand it to you – you have to fight for it. I just have to try to get to the wall first." And hopefully punch right through it.
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