The present invention relates to a device for accurately estimating the energy expenditure of a person, in particular by which the effect of cardiovascular drift is taken into account. The device comprises an input unit (10) for obtaining a movement signal (13) representing physical activity of the person and a heart rate signal (15) representing the heart rate of the person, a cardiovascular drift determination unit (16) for determining cardiovascular drift phases (17) from said movement signal (13) and either said heart rate signal (15) and/or one or more cardiovascular drift related signals (23) carrying information on one or more of amount of sweat, weight loss, temperature rise, blood lactate concentration and physical fatigue of the person, a correction unit (18) for correcting the heart rate signal (15) generated and representing the heart rate during a cardiovascular drift phase, and an estimation unit (20) for estimating the energy expenditure of the person from the corrected heart rate signal (19).
