It turns out that hula hooping comes naturally to certain people and no matter how hard others may try, they still won’t be able to keep the hoop elevated for long. A new study published by researchers at New York University is explaining why.

The hula hoop skyrocketed in popularity in the 1950s, first in Australia, and then in the United States, according to Timeless Toys by Tim Walsh. Decades later, it has remained on store shelves as a simple yet fun and challenging option for children and adults alike. Researchers looked at the hoop inquisitively, seeking to answer the questions: “What keeps a hula hoop up against gravity?” And: “Are some body types better for hula hooping than others?”

Researchers of the study, published in the Jan. 7 issue of Proceedings of the National Academy of Sciences, conducted experiments using different shapes and motions on robotic hula hoopers. They mimicked human bodies by using 3D-printed bodies that were one-tenth the size.

“These shapes were driven to gyrate by a motor, replicating the motions we take when hula hooping. Hoops approximately 6 inches in diameter were launched on these bodies, with high-speed video capturing the movements,” per a news release about the study.

Video shared by the researchers illustrate how the experiment worked, showing a robot with an hourglass form keeping the hoop in place.