Berk was born Liselotte Heymansohn in Cologne, Germany to a German mother and Russian-born father, both of whom were Jewish. Her father owned a chain of menswear shops. Berk grew up to become a ballet dancer, dancing with several prominent companies.
She later developed her own method of exercise that concentrated on the idea of building "core stability." Her style of dancing did not appeal to the British and she knew she would have to change careers to make a living. In the 1950s, with the help of an osteopath, she developed a series of exercises based on her experience with dancing. At the age of 46, Berk opened an exercise studio for women-only: the Manchester Street Studio for Exercise.
She gave certain exercises unusual names, such as "the Prostitute", "the Peeing Dog" and the "French Lavatory".
At age 50, her 30-year marriage came to an education Berk continued to teach her method of exercise well into her 80s.
Her famous clients included Joan Collins, Britt Ekland, Barbra Streisand, Siân Phillips, Edna O"Brien and Yasmin Le Bon. She died at the age of 90.
With the rise of Nazism in the 1930s she fled Germany with her husband Ernst, who was also a dancer, and her daughter.
