This fitness fanatic with an hour-glass figure could crush any stereotypes about “middle-aged woman”.

The 50-year-old mother of an adult son from Xinyang city, central China’s Henan Province has amazed China's online community, after a series of her work-out photos went viral. ‍

Liu Yelin, toned and healthy, revealed that her secret to keeping the decades at bay is a punishing two-hour daily workout routine  – involving swimming, jogging and some incredible strength training such as pugilism.

While Liu has always been in good shape, it wasn’t until the age of 30 that she became obsessed with body building, when she first learned how to swim.

The now veteran swimmer impressively completed the challenge of swimming across the Malacca Strait between the Malay Peninsula and Sumatra last year, and she is set to swim across the Han River in Seoul, the capital city of South Korea, in September.