Hottest workouts: most popular fitness concepts around the world

Group personal training and specialty exercising is all the rage right now in the fitness world. From boutique gyms, to boot camps, it's not just about working hard when you're working out.

In South Africa at Virgin Active's Alice Lane Gym, they go Safari.

"The latest class craze to sweep that Gym is called Zuu, and in that class you get to act like an animal, so literally they want you to slither on the floor like a snake, and they want you to talk on all fours like a primate," said Janice O'Leary.

In Hong Kong at XYZ Studio, cyclists exit the world and enter the luxurious hidden cave to push muscles and meditation to the max.

"Imagine the most plush spa lockerrooms, and add to that their hip and cool, dark cycling studio, they call it "the cave" and it's a great experience," said O'Leary.

In LA, Heart and Hustle is a gym so exclusive it's a favorite among celebs and pro-athletes like Reggie Bush.

"Heart and Hustle this is one of my favorite gyms, it's a boutique gym, really only two clients are ever in this gym at the same time... they have a private backdoor entrance, they'll give you a really tough workout on the most incredible equipment that exists today," she said.

While these elite gyms are taking exercise to a whole new level, in Manhattan, two new workouts are revolutionizing the way New Yorkers are working out.

At Orange Theory Fitness flat screens, heart rate monitors, and certified fitness trainers help you reach peak performance. While you work your way from the treadmill, to the rowers, to resistance training.

"OTF is a one hour workout, we operate in five heart rate zones... and the goal of the workout is to get into certain heart rate zones for 12-20 minutes, for us we call it the orange zone, it's about 84% or higher of your maximum heart rate," said Jessica Kumari, owner of Orange Theory Fitness Chelsea.

At Pursuit, there is Equinox's latest spin class. The lights go down, and big screens show how you're stacked up against the other bikers while a trainer keeps tabs on you with an iPad.

"Come on, let me see you get there, let me see you get there," said Lindsay Davis.

"I have every riders data on this iPad which is to say, not just distance and the power, but their pedal speed, their rank in the class, and how far they've ridden in throughout the entire class," said Davis.

"We are helping people get more done in a 45-minute ride than they've ever done before, and that's all about maximum performance," she said.

Personal trainers say when you turn your workout into a game, individual peer pressure can help push your limits.