Resting heart rate

A lower resting heart rate generally reflects improved endurance fitness, while heart-rate variability (HRV) is a more useful indicator of recovery and overall stress.

• Endurance training and stroke volume: Training can strengthen the heart so it pumps more blood per beat. Since resting cardiac output stays about the same, the heart can beat fewer times per minute. 1
• The under-60 guideline: A resting rate below 60 beats per minute is a useful general benchmark for fit people; a substantially higher rate may prompt questions about fitness or whether something else is going on. 2
• Stress and workout sensitivity: Resting heart rate can drift upward with sustained physical or psychological stress, but it may not register a smaller stressor such as a single hard training session. 3
• HRV and breathing: Higher HRV generally corresponds with being more recovered, while lower HRV can reflect greater stress. Exhaling—especially extending the exhale—slows heart rate through vagal pathways; inhaling can temporarily speed it up. 4 5
• Maximum heart rate: Maximum heart rate generally does not increase with fitness, so it is not a reliable measure of fitness. 6