Systems and methods for integrating and using sensor system in articles of apparel are provided. The system may include an apparel piece sized and dimensioned to be worn on a user and a sensor system integrated with the apparel piece. The sensor system may include at least one stretchable capacitive sensor positioned on the apparel piece so as to measure a biometric parameter of the user when the apparel piece is worn, an illumination system configured to provide illumination in a specified illumination area based on the measured biometric parameter of the user, and a control module to control one or more settings of the illumination system.
