Although it may look like it's all fun and games, a new study has found that hula hooping can provide a serious workout.

The study, commissioned by the American Council on Exercise (ACE), San Diego, and conducted by a team from the exercise and health program at the University of Wisconsin-La Crosse, found that a 30-minute hooping session burns an average of 210 calories. The calorie expenditure is similar to that provided by boot camp-style workouts, step aerobics and cardio kickboxing.

During the observed workouts, the study participants also achieved an average heart rate of 151 beats per minute—84 percent of the age-predicted heart rate maximum—and recorded exertion levels of “somewhat hard” on the Borg scale, according to an ACE press release.

Hoop fitness workouts, like the one the ACE study refers to, have become a hot trend in group exercise classes over the last few years. Although the hoops used in these classes resemble the brightly colored toys first launched by Wham-O in the late 1950s, today’s fitness hoops have a larger diameter and are weighted, which allows users to hoop longer and burn more calories.

“Not only can hooping workouts result in improved cardiovascular health, muscle conditioning, flexibility and balance,” says Cedric X. Bryant, ACE’s chief science officer, “but hoopers may also enjoy a fun, relaxing and potentially meditative effect due to the activity’s rhythmic nature.”

Like many fitness trends, hooping’s recent popularity has been boosted by some celebrity advocates. In a 2008 People magazine interview, President Barack Obama called his wife, Michelle, “the best hula hooper I know.” The first lady showed off her hooping skills the following year during the Healthy Kids Fair she hosted on the White House lawn.

Last year, health and wellness product supplier Gaiam introduced a “hoopBody” kit that includes a hoop and workout DVD fronted by actress Marisa Tomei. Other celebrities who have been reported to love hooping it up include singer Beyonce and actresses Liv Tyler, Selena Gomez and Nicole Kidman.