It's been called "extremely insane".
At the Sporting Club at the Bellevue, Stevan Hoffman's Extreme Fit class burns up to 700 calories. But it's not for the faint of heart.
The crossfit, the burpees, plus a crazy circuit course with tires and sledgehammer are the good stuff you need to get the fat burning.
Noah Gorson's a regular and says it's like having a personal trainer without the price tag.
"If you can't afford to have a one-on-one session with a trainer, it's great to have a good group," said Noah.
"My legs are sore the next day; my arms are sore, everything is sore," said Shilpa Sood.
At Row Zone in Center City, you can channel your inner regatta rower and paddle off some serious pounds.
"You're like, 'Oh, this is really hard!' But I'm burning like 800 calories, so it doesn't matter," said Cara.
Instructor Petar Ivacic rowed for Serbia's national team and for Temple University.
"Rowing is a full body workout," said Petar.
Petar couples sit-ups, pushups, lunges and free weight work with a hard cow rowing routine.
Over at the Sporting Club at Voorhees Town Center, some seniors are sweating at "Young at Heart" boot camp.
62-year-old Isoke Keto says her goal is to stay healthy and active during retirement.
"The more energized I am, the more I am motivated to do more," she said.
Instructor Dana Reganata keeps the class moving combining cardio and strength training.
"It is a total body workout using hand weights, balls, and bands. Everybody knows that they should do as much as they can and at their own pace," said Dana.
77-year-old Marian Insdorf says the moves have helped ease her arthritis.
"I am able to do many things that I couldn't do before," she said.
At Sweat Fitness in East Falls, a fun pastime has become the hottest fitness trend.
"I enjoy bowling, and doing the fitness thing is very exciting," said Shirley Roane.
The class is hardly a leisurely day at the lanes. The balls and pins moonlight as exercise props.
"We used it as a weight. We used it during cardio and all different muscle groups and also for bowling," said Sarah Ferri.
"I think it's a great class for people who are somewhat intimidated by the gym," said instructor Jamel Harris.
This kind of bowling burns up to 900 calories, and no, you don't have to be king or queen pin to get a good workout in. But a strike is still nice!
And here's a motivator to get started, Sweat Fitness and Frames in East Falls is offering all our Action News viewers a two week free trial membership, and that includes classes---so you can get your bowl on!
To find out how to sign up for these classes and price, visit the following websites: