These workouts are short but sweet, they may not take too long but are nonetheless intense.
"It's kind of like being a cave person and once a day you have to run from a mountain lion," said Floery Mahoney, of Lucille Roberts.
The Greenwich Village branch of Lucille Roberts has a routine that will pull you in every direction.
Mahoney invented the "Da Vinci Bodyboard" – it's eight feet long, comes with resistance bands, seems intimidating and tough, but is totally doable.
"The workout is designed to be short, intense interval training," she said.
In just 30 minutes, this class does 30 different moves.
"When you have tensions on your feet and your upper body, your core has to pull the two halves together and generally your core is the hardest part of your body to isolate and always cheats," Mahoney said, "With this opposing tension, it can't"
Similarly, the Upper West Side Equinox offers Ropes and Rowers, a high calorie, even higher energy circuit and interval training class.
"30-second round is to get your feet wet and the 60-second round is the final show," said Webb Travis, the instructor of the class.
The course has one focus in mind.
"Try to raise metabolic rate so that way you're burning calories during class and on top of that burning calories after the fact, hours later," Travis said.
Utilizing weighted jump ropes, the rowing machines and sand ropes, Travis says your body is tapping into all energy system, so that you are up for the challenge and willing to go the extra mile.
