Facebook post by University of Helsinki

Hula hooping is an effective – and an old – way to strengthen the trunk muscles and to decrease abdominal fat, proves a new study. It was created in ancient Greece but with a weighted hula hoop, it's still one powerful exercise, proves the first controlled study on hula hooping.
Shape your waist using a weighted hula hoop | University of Helsinki helsinki.fi

The decrease in waist circumference is a remarkable health benefit. In the study, the decrease gained by hula hooping was surprisingly large.