A Quotation Attributed to Hippocrates

"Walking is man's best medicine." Hippocrates

You can find this repeated all over the Internet. But did Hippocrates say it? No. See Helen King, Hippocrates Now: The 'Father of Medicine' in the Internet Age (London: Bloomsbury Academic, 2020), pp. 105-110. Why do people keep repeating it without citing an exact source? Call me a pedant, but I always want to see chapter and verse, from a primary source, preferably in the original language.