A heart rate monitor with analog and digital input mechanisms is provided with electro static discharge (ESD) protection which protects electrical components within the monitor. The heart rate monitor input mechanisms may include externally exposed sensors comprised of a conducting material, such as metal. The sensors may include push buttons, a dial, and one or more sensors for retrieving a heart rate signal, such as a case back for the monitor device. Internal circuitry such as an integrated circuit (IC) performs operations to provide time, a heart rate, and other information through a display. The ESD protection prevents any voltage discharge accumulating on the externally exposed sensors from reaching the one or more ICs and interrupting or negatively affecting performance of the monitor.