Many believe tennis simply won't offer a good workout unless you're a pro.
For the best in game tennis is a grueling sport, but for most of us there's a lot of stops and starts. It's fun but we don't necessarily burn a lot of calories. The solution is cardio tennis.
The big difference between tennis and cardio tennis: 60 minutes of swings, shuffling, muscle conditioning and fat burning.
"You're doing a lot of shoulders, you're doing a lot of core because any time you swing your racquet you're using a lot of your mid-section," said Ojakian.
He says it's tough on triceps, biceps, and the entire leg -- especially underutilized outer thighs and hips since there's so much lateral movement.
There are different levels: novice to power cardio tennis, even a mommies and me.
"It's in Greece, it's in Turkey, it's in Canada, it's in a lot of countries," said Ojakian.
Classes average $15 to $20 a session and can be done anywhere there's room to swing.
Ojakian says cardio tennis is more popular than regular tennis, the cardio concept is perfect for those wanting to improve their skills.
"You're hitting probably three to four times as many balls as you would in a normal tennis clinic," said Ojakian.
And it's fun.
"We do a lot of high fives, there's a lot of hooting and hollering, a lot of yelling and screaming," said Ojakian.
Actress Kendra Andrews tried cardio tennis as a way to keep her fitness level up when filming dance scenes in Step Up 3-D.