The life of a professional tennis player is tough as you never seem completely free to do whatever you like — even in the off-season.

Chinese star Li Na has been active on the pro stage since 1999 and understands the yearly grind and how important it is to stay even-keeled; even during the toughest of times.

"When you are competing at a certain level, people pay equal attention to your off-court life as much as your game," Li said during the Shenzhen Gemdale Open on Wednesday. "That means whatever you do can sometimes affect others, especially the juniors."

"They will get the wrong message if you relax too much. So I know that is something I can’t do — even on holidays. I like to put strict demands on myself to let the youngsters know what happens off the court is just as important if you want to be good as a pro."

Alcohol is the first item Li names on her "can’t do" list.

Li used to celebrate big wins by sharing a few drinks with friends but she has left that habit behind now.

"I definitely stay away from wine now because I have to do everything to help benefit my profession during the 51-week season."

Her healthy habits have paid off as Li’s body remains in prime condition despite her age.

The 30-year-old has been injury free since having surgery on her right knee in 2009 and regularly heads off to Germany in the off-season for specialized fitness training.

"I am lucky that injuries haven’t bothered me in recent years. That’s because I learnt how to treat my body well, with the help of my team. So, it treats me well in return."

Inspired by Argentine coach Carlos Rodriguez, Li is trying to be more aggressive on the court, coming to the net more than she used to.

That new style worked well on Thursday as she beat No 8 seed Bojana Jovanonski of Serbia, 6-3, 6-3, in 86 minutes to make the semis of the international tournament.

"Most of my main opponents have become familiar with my game, so I’d like to change it a little bit. Hopefully, it will make a difference this season," Li said.

Although the current tournament is being held in the remote Longgang district, far from downtown Shenzhen, her presence has still drawn a huge number of supporters that pack the 4,000-seat center court each day.

After her second-round victory over US player Julia Cohen, Rodriguez and her husband, Jiang Shan, were even swamped by fans who wanted to catch a glimpse of their hero.

Jiang had to climb over railings to escape the throng and took a tumble.

"He had no idea how to get out so he decided to jump over the barrier. Maybe next time he will know how to complete a better landing," Li joked after perusing her husband’s fall pictures online.

Thursday was a good day for China as another local star, Peng Shuai, overcame a first-set scare to eliminate Germany’s Annika Beck, 2-6, 7-5, 6-2. She will meet Li in Friday’s semis.

Note

Li Na will skip the National Games and instead concentrate on more pro success.

Although the organizing committee adjusted the schedule of the National Games’ tennis tournament to avoid a clash with the US Open, which will start in late August. Li said she won’t play the quadrennial event and plans to focus more on the pro Tour.

"I think more chances should be given to those young players and I won’t play it this year," Li said in Shenzhen. "I am not 20 years old anymore, so I have to plan my schedule well for consistent performances," the 30-year-old said. "I’ve talked with the team leaders of Hubei province and local sports bureau officials. They all know my decision."

Li represented Hubei at the last National Games in 2009, but pulled out in the first round due to a knee injury.