Serena Williams

Serena Williams' body has long been at the forefront of discussion during the 21-time Grand Slam singles champion's career. Compared with other tennis players, she is stockier, has bigger muscles and displays wider curves.

Serena Williams

But she loves it. It has taken her entire career -- Williams, 34, turned professional two days short of her 14th birthday in September 1995 -- to gain this confidence, as early criticism was tough on her.

"When I was younger, I wasn't really comfortable with my body," Williams said Monday night in New York City at a screening of Serena, an upcoming Epix documentary. "I just wasn't. I was like, this isn't what I'm supposed to look like. I'm supposed to be an athlete."

The film, directed by Ryan White, explains the "expected" body of a female tennis player. Players such as Maria Sharapova and Victoria Azarenka have used height and agility to stay atop the women's tennis game. Meanwhile, Williams has long been criticized -- domestically and internationally -- for having an overly masculine body. Despite no evidence, accusations of steroid use have also surrounded Williams.

"If you look at the physique of track players, of gymnasts, of tennis players, they just have a different physique, and I didn't fit that," she says. "I was one of the few people in all of women's sports who had [this] physique. And it took me a while, the strength and the courage, to embrace that and to come to feel like I love my physique. It doesn't matter what people say about you or how people feel. You have to love yourself. When you love yourself, it will manifest in everything that you do."

Williams' statements about her body came during the post-film Q&A and led to loud applause from the crowd, which included her coach, Patrick Mouratoglou, filmmaker Spike Lee and Vogue editor-in-chief Anna Wintour. Williams was also able to draw a laugh from the crowd, making a fast food reference.

"If you look at most athletes, they have a totally different figure than me. Yeah, I did -- I do -- eat a lot of Chick-fil-A."

On the topic of her body, Williams also explained a scary experience from 2011. Williams suffered a pulmonary embolism that jeopardized her life.

"I almost died five years ago," she says. "I had a blood clot that was in both my lungs, bilaterally. I actually don't even have full use of both my lungs.

"When you have a blood clot and it gets to the lungs, it's pretty much not really a good thing. It actually kills part of your lung, and it becomes black and you never get it back."

More Serena:
-- Serena Williams Pelts Balls At Male Heckler
-- Lena Dunham's Theory On Why Serena Williams, Ronda Rousey Are Body-Shamed
-- A History Of Drake And Serena Williams

Follow Jeffrey Eisenband on Twitter @JeffEisenband.