Abstract: Embodiments provide physiological measurement systems, devices and methods for continuous health and fitness monitoring. A lightweight wearable system is provided to collect various physiological data continuously from a wearer without the need for a chest strap. The system also enables monitoring of one or more physiological parameters in addition to heart rate including, but not limited to, body temperature, heart rate variability, motion, sleep, stress, fitness level, recovery level, effect of a workout routine on health, caloric expenditure. Embodiments also include computer-executable instructions that, when executed, enable automatic interpretation of one or more physiological parameters to assess the cardiovascular intensity experienced by a user (embodied in an intensity score or indicator) and the user's recovery after physical exertion (embodied in a recovery score). These indicators or scores may be displayed to assist a user in managing the user's health and exercise regimen.