Donavanik said you simply whip the ropes.
"You just undulating your entire body, and you're just moving it as powerfully and as fast as you can," he said.
Donavanik said it's a two-for-one workout: Impact-free cardio, yet a strength developer for just about every muscle in the body.
At Elevation in West Hollywood, Donavanik asked kids of all ages to take a turn, with surprising reviews.
"I like to do weights, but it's really nice to cut into your weight workout and do some circuit training like this and get your heart rate up," said fitness enthusiast Chase Hoyt.
"I'm really surprised in my arms, I didn't know they would hurt that much," said 12-year-old Cole Walker of Monrovia.
Rope width determines the workout: 1.5-inch rope for speed, 2-inch for power and offered in 30, 40 and 50 foot lengths.
Each foot weighs between 2.5 to 5 pounds, depending on the width. But don't worry, you can start with one rope, lighter ropes, shorter ropes - there's lots of options!
"No matter what age you are, no matter what athletic level, anyone can do this," Donavanik said. "For anyone who has bad knees or bad ankles, hips too, this is an awesome form of cardio 'cause there's no impact whatsoever."
Donavanik cautions those with shoulder, elbow or wrist issues to get clearance from a doctor or therapist first, then start with one rope. For the novice, Donavanik recommends 30 seconds on, 30 seconds off, working up to a 30-minute routine.
"It's intense, and I'm still out of breath," Hoyt said after a rope workout.
Waves, circles, upper cuts and hooks - some add lunges or jacks to mix it up. Bottom line, standing or sitting, the combinations are endless and challenging.
More about ropes
Gyms that use it include Breakthru Fitness in Pasadena, 345 South Lake Avenue, select Cross Fit Gyms and Elevation Fitness in West Hollywood, 8535 Santa Monica Blvd.
To try it at home, ropes range in price. For beginners or people on a budget, you can buy nylon rope at Home Depot for roughly $1.50 per foot (higher end rope). You ideally want a rope that's anywhere between 30-50 feet, depending on space constraints and where you would be using it, but the longer the better.
If you want heavy duty ropes, those will cost between $90 and $220 for 30-50 feet. Between nylon or manila rope, manila rope is cheaper but tends to shed a little.
The rope needs to be secure! Use a big hook-and-eye for the ground or wall stud, tied around a tree or something very heavy. Many tape their ends to keep them from fraying.
People can definitely do this at home with minimal training. It's all about developing a movement pattern and because you can visually see what the ropes are doing, it's that much easier to make adjustments to your technique in real time, unlike something like running, where you don't necessarily see yourself unless you watch it on video.