Olympic stars Lisa Buckwitz and Janine Flock bared all before heading to Beijing ... by posing nude for Playboy to promote body positivity!!
Buckwitz -- a gold medalist in 2018 Winter Olympics -- wore only an open green top and black heels in her cover shoot for the popular mag's Germany edition.
Flock -- a 10-time world champ -- sat nekkid in a chair draped in a fur blanket for her cover.
27-year-old Buckwitz said she jumped at the opportunity to be photographed in the buff to encourage women to maintain a positive perception of their body.