Bradycardia is slowing of the heart rate below 40. They can be caused by various medications that affect the conduction system ( electrical system) in addition to damage to the heart muscle that affects the electrical system of the heart. If you have symptoms of lightheadedness, or passing out you will need a pace maker.

Bradycardia in athletics is very normal. As long as you have no symptoms yes it is normal

It could be medication or physiology of the person. He may jog a lot.

There can be many causes of bradycardia, so you should see a cardiologist so he or she can do an appropriate work-up and see if and when treatment may be needed.

Athletes well-conditioned can be slow, which is normal. Less than 50 in most is too slow. Lots of causes. Medications like metoprolol can do that, and others. Some over-the-counter pills can cause it. Hard to cover everything without a doctor visit and full history and physical. I would get checked out if you are slower than 50.