She outplays women half her age on the tennis court.
Her accomplishments include 59 grand slam titles, with a record nine Wimbledon singles championships.
But Martina Navratilova says the toughest opponent of all was cancer.
She was diagnosed with grade three DCIS (Ductal Carcinoma In Situ) breast cancer earlier this year and underwent a successful lumpectomy to remove the cancerous cells on March 15.
"Throughout my decades-long tennis career, I have faced some really tough opponents across the net – Chris Evert, Steffi Graf, Monica Seles, and even the Williams sisters in doubles, “ she said. “What I never anticipated was that my toughest opponent would be off the court: cancer."
CNN International was granted rare access to document Navratilova's treatment and recovery, and shared Navratilova’s story this weekend in "Martina: My Toughest Opponent" http://www.cnn.com/2010/SPORT/tennis/08/05/navratilova/
She decided to tell her story because she wants women to take better care of themselves and get regular mammograms -- not put it off like she had.
When asked if this was a time of forward thinking or reflection, Navratilova said: "I'll think about it, but I'm just thankful that I caught it when I did, that I didn't wait another year and think, Oh, I'll just do that mammogram later. I'll be very meticulous now about going to the doctor and getting those six month check ups and one year check ups. I'm not going to let that lapse again."
Named one of the Top 40 Athletes of All Time by Sports Illustrated, Navratilova hopes to raise of awareness about the importance of preventative health screenings. A long-time advocate of healthy life habits, her advocacy work has including being the Health and Fitness Ambassador for AARP and writing a monthly fitness column for those over age 50: http://www.aarp.org/health/experts/martina/
"The day I was told I had breast cancer was my own personal 9/11,” she said. I was completely shocked and the news literally knocked the wind out of me. This is a huge wakeup call for me and just goes to show no matter how much you watch what you eat or exercise, you just never know.