A device for determining a heart rate of a user has a PPG sensor and an accelerometer to compensate for acceleration artifacts within the PPG signal. The device transforms time domain PPG and accelerometer signals into the frequency domain using a Fourier transformation and utilizes the Fourier coefficient magnitudes as indicative of the probability of candidate heart rate values. Candidate heart rate values are determined at sampling times over a time interval and a most probable heart rate path during the time interval is determined using a reward/penalty algorithm.