Cardio Tennis is a fun group activity for anyone, at any playing level, looking for a fun way to burn calories & interact with others outside of the gym. Cardio Tennis is a high energy fitness that combines the best features of the sport of tennis with cardiovascular exercise, delivering the ultimate, full body, calorie burning aerobic workout. Most women can burn 300 to 500 calories per hour and men burn between 500 to 1,000. Not only are you getting a great workout, but you are also learning a skill and training for tennis.