The rate at which your heart beats when it is resting is a determinant of your physical fitness and also indicates how your hormones and nervous system are operating. A normal resting heartbeat is one that beats 60-100 times per minute and it is accepted medical wisdom that those who are most physically active will have a lower resting heart rate.
New research in Denmark has now revealed that the risk of death is higher the higher the resting heart rate, no matter how fit an individual is. Researchers examined the data of around 3,000 men who had been participating in the Copenhagen Male Study since 1970, which had been established to monitor the cardiovascular health of middle-aged men.
The men’s cardiorespiratory fitness was assessed at their initial participation in the study, while they were quizzed about their health and lifestyle, such as exercise and smoking. A decade and a half later, they were given a further check-up that measured height, weight, blood pressure and blood glucose, and their resting heart rate was also noted.
By 2001, 39% of the men had died and the researchers examined their data to explore if heart rate affected the death rate. Their study confirmed the conventional wisdom that the men with a high resting heart rate were less physically fit than others, had higher blood pressure and were heavier, while men who were physically active had lower resting heart rates.
What their study did reveal was that regardless of fitness levels, a higher resting heart rate brought a higher risk of death. A resting heart rate of 51-80 bpm (beats per minute) brought a 40-50% increased risk of death. At 81-90 bpm, the risk of death doubled when compared with the men who had the lowest rate of bpm.
The researchers concluded that ever 10-22 additional bpm in a resting heart rate will increase the risk of death by an overall 16%. Smokers face a higher risk when compared with non-smokers.
The study suggests that a high resting heart rate is not simply an indication of a person’s poor physical fitness but should be considered as an independent risk factor for death.