My 1st Gym opened in Lilydale this month, formally launching its services with a visit from the Richmond Tigers last Thursday.

Catering for children aged six to 15, it has strength training equipment similar to that found in an adult gym, but adapted for its younger members.

It also has fast-paced interactive machines that use sound and light to improve reflexes and agility, treadmills, rowers and interactive bikes and dance mats.

The gym's schools consultant, Yvette Roless, said members included children from sports clubs who wanted to improve their performance as well as those who did not feel comfortable in a sporting environment.

Schools groups also use the facility, with year 7-9 students of Lilydale Adventist Academy who are not involved in school sports taking part in a fitness class last Thursday.

Ms Roless said members trained for up to an hour under the supervision of qualified instructors.

Monash University's Associate Professor Robert Griffiths, who specialises in exercise, said the concept sounded good, especially if it meant girls in their mid-teens did more resistance training.

"If they can get them in, that's the time you lay down the foundation for bone mineral density later in life to prevent osteoporosis."

He said that as long as those taking part were properly informed and supervised and used only lighter weights, "resistance exercise is good for all ages from very young to very old".