Ana Ivanovic is a Serbian professional tennis player, who ranked number 1 in the world in 2008.  She began competing professionally in 2003 when she was just 15 years old, and has since won 15 WTA Tour singles titles, including one Grand Slam singles title.  She became the first Serbian woman to win a Grand Slam title after beating Dinara Safina in the final of the 2008 French Open.  Now, at 29, she has announced her retirement.

In September, Ivanovic said that she won't be retiring, even after suffering another US Open first-round exit inside 79 minutes during a match with Denisa Allertova. The same month, she was advised by to rest by her doctor due to a recurring wrist problem. She also revealed that she had been delaying a surgery for a broken toe which resulted from a match during last year's Australian Open.

According to ESPN, Ivanovic was consistently injured. "I can only play if I can perform up to my own high standards, and I can no longer do that, so it's time to move on," the tennis star said.  In 2008, she began struggling with injuries and dropped out of the top 20 the following year. 

She did manage to return to the top five in 2014, but more injuries took their toll. "But I was mentally so strong, fighting my body and getting through these matches," she said in an interview with WTA.

On December 28, she made an announcement via Facebook Live that she will be quitting for good.  "There is no other way to say it, I've decided to retire from professional tennis," Ivanovic said. 

Meanwhile, another sportsperson, Great Britain's most decorated Olympian and cycling supremo Sir Bradley Wiggins, also announced his retirement on Wednesday.  Wiggins is the most decorated cyclist in Britain.  Part of Wiggins' social media post said: "2016 is the end of the road for this chapter, onwards and upwards."