"I was told I didn't look like a gymnast. I was told I looked like I'd swallowed an elephant, or looked like a pig."

After a video of American gymnast Katelyn Ohashi performing a 'perfect 10' routine went viral in January, many on social media focused on her "infectious passion" and the fact she looked "so fun".

But the joyfulness of the performance told nothing of the difficult journey she had been on.

Ohashi was tipped for global success when she beat compatriot Simone Biles - now a four-time Olympic champion - in the 2013 American Cup.

But a back injury ended her elite career - and when she returned to the gym after taking a break, she began to struggle with body image.

"I was trying to work through the pain and crying literally every turn I took," said the 22-year-old. "A coach was upset I had put on weight - he said it was why it was hurting.

"As gymnasts, our bodies are constantly being seen in these minimal clothing leotards. I felt so uncomfortable looking in the mirror.

"I felt uncomfortable walking back into the gym, like there were eyes just targeted at me. I hated taking pictures. I hated everything about myself.

"Even being home was hard. My mom's super skinny and super healthy and she'd be like, 'let's go swimming' and I'd be like, 'I'm not getting in a swimsuit in front of you'."

Ohashi's perfect 10 routine has had more than 40 million views on YouTube

'A form of abuse'

Body image is described by the Mental Health Foundation as "a term that can be used to describe how we think and feel about our bodies".

And a recent survey of 4,500 UK adults found a third had felt anxious about their bodies.

Ohashi, who started gymnastics at the age of three, says comments from others made her feel self-conscious as a teenager.

"You start normalising things because that's what you know and you grow up surrounded by people that are going through the same thing as you, so it becomes what you expect almost," she said.

"But when you look back on it, I do think it's a form of abuse. It was common, especially in the elite world."

Looking back, Ohashi describes her 16-year-old self as "abnormally skinny".

"Me and my friends would create sick jokes, not jokes but games like we wouldn't eat because we didn't understand what we were doing to our bodies and how dangerous that is," she added.

'Disastrous' effects

Gymnastics coaches run a higher risk of provoking body-image issues in their athletes because of the focus placed on appearance in the sport, according to Dr Jill Owens, a chartered sport and exercise psychologist.

"It can be a lot more complicated when there's an aesthetic element to the sport - like gymnastics," she said.

"Coaches in those kinds of fields have to tread even more carefully because in the past those sports have been associated with leanness and there's an element of being judged on how the sport appears.

"Because the body is such an obviously integral part of sport, it's vital that it is regarded positively.

"Subconsciously, if we're thinking negatively about it, we're much less likely to look after it properly. In sport, that's disastrous.

"It might go a stage further than that and we might be looking after it in an unhealthy way by not eating enough or by overtraining."

The weight of society's expectations

While gymnasts can feel pressure to be lean, athletes in other sports generally need a larger frame - and in some cases a body shape that some would consider unfeminine.

One such sport is rowing, in which competitors are usually tall and powerful with broad shoulders.

Olympic silver medallist Vicky Thornley was initially uncomfortable with that, but her rowing career has transformed her relationship with her body.

"Before I started rowing, I wanted to be a model," she said. "I wanted to be really thin and not have any muscle.

"I speak to some junior rowers and they say: 'I don't want to get really muscly.'

"I'm horrified now that I even thought about those kinds of things. I never thought the person back then would want to be more muscular. I'm constantly trying to put more muscle mass on.

"I love it when my arms look big and I've got a vein coming out or whatever. I'm aware some people might not think that's attractive but it makes me feel stronger and more empowered when my body feels strong."

Vicky Thornley (right) won double sculls silver with Katherine Grainger at the Rio Olympics

Turning things around

Ohashi experienced a turning point with her body image too. It came when she began studying at the University of California, Los Angeles (UCLA), from where she recently graduated with a degree in gender studies.

She initially told her coach at the university that she "didn't want to be great again" because she "correlated greatness with misery", but says she was given the support she needed to succeed.

"Coming to UCLA and being pushed to go to the psychological services, being surrounded by a coaching staff which really puts athletes as people before the sport itself, has definitely been crucial in my growing as a person and my mental health," she said.

"Now I've been wanting to do this whole women thing. I go for women empowerment.

"Everybody's bodies are different and there's not a single body that is the perfect body because there are constant trends.

"Being comfortable with the only person that matters, yourself, is something that you can forever work towards. You're the only person that has your back and you're the only person that has your skin 100% of the time."

Reporting by Becky Grey, interviews by Jo Currie, Emma Cook, Kate McKenna and Melissa Sharman.

For details of organisations which offer mental health advice and support, visit bbc.co.uk/actionline

BBC Sport has launched #ChangeTheGame this summer to showcase female athletes in a way they never have been before. Through more live women's sport available to watch across the BBC this summer, complemented by our journalism, we are aiming to turn up the volume on women's sport and alter perceptions. Find out more here.