Fitness brand Reebok introduces PureMove, a sports bra that contains shear thickening fluid (STF), a gel-like solution that is liquid in a still or slow-moving state, but stiffens and solidifies when moving at higher speeds.

According to Reebok, 1 in 5 women avoids exercise because they don’t have the right sports bra, and 70 per cent of women wears the wrong size.

Rather than using more fabric, straps and hooks to keep everything in place during exercise, Reebok’s sports bra has a minimalist construction, comprising only of 7 pieces of fabric. Perforation in the front and back are added to keep you cool.

The secret lies in the technology, STF. This gel is a non-Newtonian fluid, which means it does not follow the law of viscosity. The material is liquid when still, but turns solid when in motion – making it a perfect material to use in a sports bra.

STF was originally developed as a form of armour technology. In 2002, researchers at the U.S. Army Research Laboratory and University of Delaware started researching its use in body armour. STF armour is flexible in a normal range of movement, but when faced with a stabbing knife blade or piecing bullet, it turns rigid. Since then, the material has been used in everything from Kevlar bulletproof vests to NASA space suits.

Reebok’s motion sense technology is the result of treating a performance-based fabric with STF. “The fabric adapts and responds accordingly to the body’s shape, velocity of breast tissue, and both type and force of movement,” Reebok states. This makes sure that the bra stretches less with high impact movements, preventing the wearer’s breasts from bouncing about, and provides light support during rest and lower intensity activities.

Photos: Reebok