During exercise, your heart rate increases to pump more oxygen-rich blood to your muscles.
This is because the muscles need more oxygen to produce energy and support their increased activity.
When you exercise, your body sends a signal to your heart to beat faster and pump more blood.
This increase in heart rate is a normal response to the body's increased demand for oxygen.
Additionally, the release of adrenaline and other hormones during exercise also contribute to an increased heart rate.