An ambulatory electrocardiogram with a fast heartbeat from exercise will show tachycardia. Normally ambulatory ECG is able to monitor changes in heart rate for 24 hours. If exercise is performed during the monitoring process, which results in a fast heartbeat, the heart rate will be physiologically elevated for a short period of time, and the final result of the test may show sinus tachycardia. Heart rate fluctuates with age, gender, and physical activity. Normal people may experience an increase in heart rate after emotional excitement, alcohol consumption, physical activity, exercise, smoking, and drinking tea, and an increase in heart rate after fever, hyperthyroidism, and the application of medications such as epinephrine, which can lead to sinus tachycardia. It is recommended not to exercise, smoke, drink alcohol, etc. during the dynamic electrocardiogram examination to avoid influencing the examination results; if sinus tachycardia occurs, it is recommended to consult a doctor in time for treatment after a comprehensive assessment of the condition.