Articles of athletic garments, particularly sports bra and methods of treating the athletic garments with a shear thickening fluid (STF) are disclosed. The athletic garment comprises a STF treated fabric. The STF treated fabric in contact with the wearer's body part restricts movement of the body part when the shear stress exceeds the shear stress threshold value and stretches and conforms to the wearer's body part when the shear stress is less than the shear stress threshold value. The STF treatment method may include immersing the untreated fabric in a diluted STF bath, metering an amount of the fluid on the fabric, and removing the diluent from the treated fabric.