Abstract: The present invention relates to a method and apparatus for having a fabric that is able to indicate heart rate zones by using colour indicators which comprises of one or a plurality of sensors embedded in the fabric for the detection of heart rate and the signal from the sensor is transmitted to at least a microprocessor whereby the output from the microprocessor will drive at least one or a plurality of light emitting devices and audible signals will be produced. The emitted light is propagated through a medium providing a visual indication to an observer of heart rate zone on the fabric. The audio signal is driven by output signal from the microprocessor to indicate different heart rate zones. Said medium is attached or woven into natural or synthetic yarn to produce light transmitting fabric that reveals different colours. Said sensors, microprocessor and light emitting devices are embedded or attached in the fabric.