Various systems and methods for monitoring oxygen saturation are provided. A monitoring system may include a sensor configured to obtain a physiological signal and a monitor configured to obtain the signal from the sensor and to determine a baseline oxygen saturation from the physiological signal and to generate one or more zones based at least in part on the baseline oxygen saturation. Each zone may include a different range of percentages of oxygen saturation and at least one of the zones corresponds to an anaerobic exercise condition.
