Disclosed is a muscle toning garment configured for use with modular, interchangeable resistance elements. The garment provides resistance to movement throughout an angular range of motion. The garment may be low profile, and worn by a wearer as a primary garment or beneath conventional clothing. Toning may thereby be accomplished throughout the wearer's normal daily activities, without the need for access to conventional exercise equipment. Alternatively, the device may be worn as a supplemental training tool during conventional training techniques.