For all Vivafitness products with functionalities linked to heart rate: the heart rate values provided from the chest belt or hand sensors are specifically designed to display the heart rate only. Any other use is excluded, diagnostic or medical; it does not see any anomalies or cardiac dysfunctions. The use of the heart rate chest belt is not suggested in the presence of a pacemaker or similar medical devices. In the case of medication that can affect the heart rate, the value can be altered. Always consult your doctor before starting a physical activity regime and prior to using devices specific to heart rate functions.