(CNN) -- Boxing, yoga, beach volleyball, kayaking, ice-skating and episodes of the television show "Glee" -- the stars of women's tennis are testing and resting themselves as they gear up for a hectic 2011.
It was little over six weeks ago that Kim Clijsters lifted the WTA Championships title in Doha to signal the end of another action-packed season on the tour.
The Belgian and her fellow professionals could be forgiven for wanting an extended period of rest given the intense physical pressure put their bodies during the 10-month-long campaign.
But with the Australian Open looming large on the horizon in January, there are women dotted all over the planet being taken to task by personal trainers, keen to fine-tune their fitness for the grueling year ahead.
Clijsters, who retained her U.S. Open title in 2010, is taking the battle to get fighting fit literally, by introducing boxing into her training regime alongside the more genteel pursuit of yoga.
Her coach Wim Fissette told the WTA Tour website: "The difference between boxing and tennis couldn't be smaller: similar footing, coordination of both eyes and hands, focus -- it simply is all beneficial for a tennis player, too."
Clijsters agrees: "This is a great change from the usual base training. It was quite tough initially, but after a few weeks it is starting to pay off already."
World number two Vera Zvonareva managed to squeeze in three weeks of holiday before getting back into training in Florida. For the Russian, the emphasis is firmly on fitness.
"I am only training on court for about two hours and then I am in the gym about four hours," she said.
"As I get closer to the start of 2011 I will gradually increase my time on court and spend less time in the gym.
"This is the time of year where we start fresh and really build the base for the upcoming season. It is a really good time to also evaluate your past season and look at areas where you need to improve.
"When I am not training, I like to watch movies, catch up on Glee and some other shows and sleep! Sometimes you can never get enough sleep."
Serbia's Ana Ivanovic, who is back up to 17th in the world after falling down the rankings following her 2008 successes, prefers a less rigid regime.
"One of the keys to successful training, in my opinion, is to keep things as varied as possible," the former No. 1 said. "I've been doing some fun things like beach volleyball and basketball, and I've been lucky enough to go running among some beautiful landscapes.
"In the gym we make things interesting too, with yoga, music and even some boxing movements. Of course, I also do more traditional stuff like weights and the treadmill, but these are the most interesting activities!"
World No. 6 Sam Stosur has even enlisted the help of the Australian kayak team at their base on the country's Gold Coast in a bid to boost her fitness levels for the new season.
"It is a lot of fun and they work very hard so I really enjoyed doing a sport which I have not done before. Trying to keep up with the other girls was very tough," the French Open runner-up said.
"The best part of the offseason is the chance to catch up with family and friends in a relaxed environment without knowing I have to jump on a plane the next day and fly across the world."
Israel's Shahar Peer is in Miami staying with a Jewish family and training up to five hours a day.
"Unfortunately, I will not eat Sufganiyot [traditional Israeli deep-fried doughnuts]!" she said.
"We had many plans that have nothing to do with tennis -- going to restaurants, basketball matches, sightseeing, nature trips, movies -- but the whole team is too tired so none of the above is done!"
While Victoria Azarenka's coach focuses on "correcting functional weaknesses and muscle imbalances" to ensure the Belarusian's joints are all working in unison, French player Marion Bartoli prefers a game of volleyball or squash to add variety to her regime.
South Africa-born American Liezel Huber might be sitting at three in the doubles rankings but she doesn't get the star treatment at home, mixing lawn-mowing on her Texas ranch with more conventional exercises.
World No. 24 Flavia Pennetta already sounds tired of her preseason preparation.
"My daily regime is pretty much the same as last year -- this means training, training and training!" she said.
"Preseason training is very important because it is the time to work on the faults, to analyze what must be done better in the New Year."
Svetlana Kuznetsova spent two weeks back in Russia with her parents and even watching her favorite soccer team, Zenit St. Petersburg. Her fitness training started back in November before she flew to an exclusive Dubai hotel to train in warmer climes.
"The managers told me it is just me who will be practicing there this December and some other guy named Roger [Federer]! It will be a slightly different regime in Dubai as I can swim and jog outdoors between my on-court practices," she said.
Japan's Kimiko Date Krumm is hard at work, trying to make sure she can replicate her success of 2010, when at 40 she came close to winning the Japan Open and becoming the oldest player to claim a WTA Tour title.
She had just one week off before preparations began in earnest for what will be her final season on the tour, heading to the south of Japan to build up her fitness before flying into New Zealand after Christmas.
World No. 20 Maria Kirilenko is another player with her nose to the grindstone, working up to five hours a day, but she values her time away from the gym highly.
"I have half a day off once a week and I am enjoying that moment with my friends. I like ice-skating, sometimes if I have time I love to do it," the 23-year-old Russian said.
"Preseason is so important because you have to be strong and fit for the New Year. I'm hoping to be a better player in 2011 and to be healthy."