Final answer:
A resting heart rate of less than 60 bpm is termed sinus bradycardia, and while it may be normal for athletes, it can indicate health concerns if accompanied by other symptoms.
Step-by-step explanation:
A resting heart rate of less than 60 beats per minute (bpm) would be regarded as sinus bradycardia. This condition can be normal for well-trained athletes who often exhibit lower heart rates due to their high level of cardiovascular fitness. In the general population, while a resting heart rate within the range of 60-100 bpm is considered normal, a heart rate below this range is classified as bradycardia. However, unless accompanied by other symptoms such as dizziness, fainting, or shortness of breath, bradycardia is not usually clinically significant. It's important to consider accompanying symptoms and overall health context when evaluating the significance of a low heart rate.