Video: Trailer for Venus and Serena

Venus and Serena, a documentary that followed the sisters during their tumultuous 2011 season, will debut on iTunes on Thursday and hit theaters on May 10.

The Williamses gave the filmmakers unprecedented access during a year in which Serena was hospitalized with blood clots in her lungs and returned from an 11-month absence, and Venus struggled with injuries and illness. Both sisters mounted comebacks that eventually put Serena back on top of the women's game and netted Venus another Olympic gold medal.

"I wanted people to see everything I went through, and it wasn't easy," Serena said Monday in Charleston, S.C., where she's competing at The Family Circle Cup. "It was just a great time to capture in my life. I wasn't doing that great and I had just fallen from grace, so to say. And you really see all the hard work from the beginning. I won Stanford [in the summer of 2011], I won Toronto and then I get to the finals of the [U.S.] Open, and you can see the history of me getting back to where I am now. That was kind of cool."

I'll have more on the movie later this week. For now, here's a look at the trailer: