We all know tennis players have some of the most beautiful physiques around. Now there is a fun way you can benefit from their workout secrets even if you have barely touched a racquet - cardio tennis.
Founded in the US in 2005, cardio tennis launched in Australia in January and has been taking our courts by storm, with already more than 300 coaches.
Cardio tennis leader Travis Atkinson said it was a fun, social, group tennis-fitness program for all ages and abilities.
"It's more about getting a great, high-energy workout than pure tennis technique," he said. "Cardio tennis is an excellent total body workout. Leading cardiologists have stated that programs such as this can lead to an increase in life expectancy because people who exercise regularly live longer and have less incidence of stroke and cardiovascular disease."
As well as the cardio aspect, the kilojoule burn was another major benefit.
"Women can burn around 1260 to 2100 kilojoules (300 to 500 calories) and men 2100 to 3360 (500 to 800 calories) per hour," he said.
Tennis Australia cardio tennis coach and mentor Christina Ladyman, who is an exercise physiologist, said the program appealed to people who loved fitness, tennis and having fun.
"If you ask most people to sum up cardio tennis in a few words, fun is always mentioned," she said. "There are lots of games played, so the class creates a real social aspect."
Ms Ladyman said anyone could play, regardless of ability.
"The class is less about instructional technique and more about getting an awesome cardio workout while playing tennis," she said.
"I've run classes where I have ex-professional tennis players on the same court as complete beginners and both get the same cardio workout, benefits and enjoyment."
A session includes a warm-up, a cardio section of drills and games, and a cool-down.
Ms Ladyman said participants moved for the whole class, with constant ball hitting, moving through ladders and other "cardio bursts" like toe taps and scissors.
"The music played is mixed to be upbeat so people feel like they want to move," she said. "Participants wear a heart rate monitor so the coach can gain an idea about fitness levels and how hard the players are working."
Mr Atkinson said cardio tennis improved your game, too.
"With fitness gains and an emphasis on getting as many balls back into play as possible, over time your game is sure to improve," he said.