If you’ve ever tried carrying an aquarium full of water, you’ll know that not only is the stuff heavy, but that things can get tricky when it starts to slosh back and forth. The Attitube, a relatively new fitness training device, takes advantage of those qualities to build core stability. Designed by Canadian former professional wrestler and present-day strength and stability coach Larry Brun, the Attitube is a simply a clear hollow tube with water inside. You use it like you would a barbell or dumbbell, with the motion of the water adding an extra challenge for your core muscles.

The Attitube comes in different sizes, each one with a marked weight range that can be adjusted by adding or removing water (although Brun says they work best when half to three-quarters full). As the user lifts the device up and down or back and forth, the water sloshes back and forth within the tube. Compensating for that movement, or trying to minimize it, is what is claimed to build the core.

Brun also promotes his product for use in yoga, as he says it encourages balance.

In 2007, the Attitube won the Everlast Award for the Best Concept and Marketability in Fitness at the INPEX Inventors Show. The Pro model, which has a 6-inch (24cm) diameter tube and integrated handles, is currently part of a study at the University of Windsor, to assess how it compares to other forms of training.

A set containing an Attitube Original barbell and two dumbbells can be purchased for $139.95 (not clear if those are Canadian or U.S. dollars) via the Attitube website.

Via Dragons' Den (Canada)