More than three decades later, the ex-librarian, who has already retired, doesn't look much older. With glowing skin, a super-toned body and not a single wrinkle in sight, China-born Ms Liu has stunned millions of people with her incredibly youthful looks. 'People are often shocked to find out I'm almost 50,' Liu Yelin, 49, told MailOnline.
'Whenever I went shopping and told people my real age, I often got mobbed by strangers who wanted to find out my secrets.'
Ms Liu then shared with us her motto: 'If you think you look rough, that's because you haven't sweated enough.' Liu Yelin, who is also known by her screen name Ye Wen, was born in 1968 in Xinyang, central China's Henan Province.
The confident and energetic retiree said her age-defying appearance has caused her headache. People who don't know her often mistake her son, 22, for her boyfriend.
Ms Liu said once she went to attend a friend's wedding with her son, who works as an assistant at a film production company. She was pestered by many guests who wanted to find out if the 22-year-old was her new partner.
Although the active mother has enviable olive skin and flawless complexion, she claimed that she rarely uses cosmetics.
Instead, Ms Liu, a fitness fanatic, attributes her youthful looks to the regular exercise she's kept to for three decades.
'I swim in the lake and do weight training every day,' she said. 'My favourite thing is swimming outdoors in winter.
'When everyone was wearing down jackets, I had to strip down to my bikini and dive into freezing water. It's a test for my will and perseverance. I often had to force myself to do it.'
Nevertheless, 30 years of sub-zero swimming has helped Ms Liu build a body even supermodels find hard to compete.
On Ms Liu's social media account, she flaunts her firm figure daily by updating photos which show her in bright sportswear or attractive bikinis.
They have not only attracted nearly 75,000 social media followers for Ms Liu, but also caught the attention of dozens of TV directors, who fought to get her on their programmes.
Above all, Ms Liu said her tough workout regime has sharpened her character and made her the strong, straightforward person she is today.
The mother has swum across the Yangtse River in China and the Han River in South Korea.
In March 2016, she set a challenge for herself: to swim across the sea for the first time. She successfully crossed the Strait of Malacca after setting out from the shores of Penang, Malaysia.
'It's probably the hardest thing I have done in my life so far. I was used to swimming in rivers and lakes, but I had never swum in the sea.
'I struggled because my goggles were leaking and my tongue hurt so much from touching seawater.
'I felt as if there were dozens of cuts on my tongue, and when the salty seawater flowed into my mouth, it was unbearably painful.'
Despite the ordeal, Ms Liu successfully crossed the choppy channel after swimming 12 kilometres (7.48 miles) non-stop. It took her four hours.
She was still excited when she described the life-changing experience: 'For me as an ordinary person, it was a big challenge and a great success.'
After conquering the hearts of the Chinese public, Ms Liu said her next goal is to travel around the world.
'I'm a spontaneous person, so I might pack up my bag and travel to Europe on a whim.'
She also said: 'I want to stay this beautiful when I'm 80 years old.'
The woman then concluded: 'I share my brightside stories because I want to encourage more women to keep up exercising for a more beautiful and confident self. always look on the bright side of life and stay positive.'
She added: 'I feel like I'm still 15.'
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50 Year Old Mother Looks So Young People Think Her Son Is Her Boyfriend! Asian Beauty Secrets & anti-aging secrets.
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