I'm 29 years old and I've noticed that my resting heart rate is usually between 50 and 60. However, sometimes when I check it in the morning right after getting up, it shows numbers like 46 to 48. During a 2 km run, my heart rate shoots up to 160 or 170, and while walking, it's around 90 to 120. My ECG results have all come back normal, so Im wondering if my low resting heart rate is something I should be concerned about. Is this normal?

A resting heart rate between 50 to 60 beats per minute is considered normal for adults, especially for individuals who are physically active. It can be a sign of good cardiovascular fitness. However, if you are experiencing symptoms such as dizziness, fainting, chest pain, or shortness of breath along with the low heart rate, it is important to consult a doctor for further evaluation. Since your ECG reports are normal, the low resting heart rate is likely due to your good physical fitness level. During exercise, it is normal for the heart rate to increase significantly, as you mentioned reaching 160-170 beats per minute while running. This response is expected and shows that your heart is able to adapt and meet the increased demand for oxygen during physical activity. Overall, based on the information provided, your heart rate variations seem to be within normal ranges for someone who is physically active and with normal ECG results.