The American T'ai Chi Associates recommends looking for a school that adheres to the original principles of the martial art it offers, rather than one that dilutes them by, say, pairing jujitsu with kickboxing: The purer the teaching, the more your child stands to gain.
The mean calories burned per minute of tennis, based on the list of 5 activities, shown below, for an average male, weighing 190 pounds (86 kg) is 9 Calories per minute. The average per minute for an average female, weighing 163 pounds (74 kg) is 7 Calories per minute.
Most people overestimate the number of calories they burn with exercise and are unaware of the calories in everyday food -- particularly fast food. For example, for the average person, one hour of high impact aerobics, vigorous weight training, circuit training or playing basketball, will burn about 500 calories.