What is the typical resting heart rate for an adult human?
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Answer: A. 60 to 100
Explanation
The normal resting heart rate for a healthy human adult ranges between sixty and one hundred beats. Values within this physiological window indicate that the heart pumps blood efficiently at rest. Cardiologists use this standard range to evaluate basic cardiovascular fitness and metabolic health. Resting heart rate is measured when a person is calm, relaxed, and inactive for several minutes. Athletes often have lower resting heart rates due to enhanced stroke volume from cardiovascular training. The sinoatrial node acts as the natural pacemaker generating these rhythmic electrical cardiac impulses.
Tachycardia occurs when resting heart rate exceeds one hundred beats per minute persistently. Bradycardia describes a resting heart rate dropping below sixty beats per minute in adults. Regular physical exercise helps maintain a healthy resting heart rate and reduces cardiovascular disease risks. Seventy to one hundred is too narrow since the recognized lower limit starts safely at sixty beats. Fifty to one hundred includes bradycardia levels that are generally below normal for average adults. Eighty to one hundred excludes lower healthy resting heart rates commonly observed in physically fit individuals.
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