Whoa. Check out Sam Stosur's guns.

The Australian tennis pro quietly debuted her ultra buff body during a practice session in the sweltering heat at Sydney Olympic Park Tennis Centre on Sunday.

It's all thanks to Tennis Australia's strength and conditioning expert Stefano Barsacchtre, who has been working with Stosur, 31, since November in a bid to improve her recent disappointments on court.

It comes ahead of her Sydney International campaign which kicks off Monday afternoon, when she faces Italy's Roberta Vinci, a great practice run ahead of her 13th Australian Open which starts next week.


"We've changed things a little bit, we're probably spending more time on the tennis court than in the gym, she has started to run much more than before, interval sprints, these kind of workouts make you a little bit more lean," Barsacchi told the Daily Telegraph.

"Sam has always been really fit in her career. I wouldn't say she is more or less fit now, but probably with the drills we have been doing she is more well prepared in tennis-related fitness and agility, and that's the way tennis has been going in the last three or four years, you just have to look at Novak Dkjokovic.

"I think she is really professional. When an athlete her age still works really hard on and off the court and accepts a change of philosophy of the work, which even for her was a little bit hard, the kind of mentality she has is great.

"It is an example of how athletes should be. I think she will improve, but this is just the beginning."

- news.com.au