A new study in Journal of Epidemiology and Community Health finds that people who have high resting heart rates (over 100 beats per minute) are significantly more likely to die from heart−related issues than people with lower heart rates. This disparity was particularly true for women, the researchers say.

In the study, Javaid Nauman and colleagues at the University of Norway followed over 50,000 men and women who had no heart problems at the study’s outset. They tracked the participants for an average of 18 years, over which period 4,380 individuals died of heart−related causes. Overall, the researchers found that women with heart rates over 100 BPM had a 42% greater likelihood of dying from heart−related causes than women whose heart rates were considered normal. They found that for women under 70, every increase of 10 beats per minute (BPM) corresponded to an 18% increased risk of heart−related. (This trend was not found for women over 70.)

But there was a caveat to the study’s findings: women who had high levels of physical activity, even if they had high heart rates, were less likely to die of heart−related causes than women who were relatively inactive.

In men, the risk increase for heart−related deaths was about 10% for every jump of 10 BPM. Men whose heart rates were over 100 BPM had a 73% greater likelihood of dying from heart attack than men whose heart rates were in the normal range.

But there was a caveat to the study’s findings: women who had high levels of physical activity, even if they had high heart rates, were less likely to die of heart−related causes than women who were relatively inactive. Those who had heart rates over 88 BPM had only a 37% increased risk of death from heart attack, while inactive women were twice as likely to die from heart−related causes. The same protective effect was not observed in men.

The authors say that theirs is the first study to tease apart the relationship between heart rate, activity level, and risk of death. They conclude by saying that for people who have high heart rates, physical activity may “substantially” reduce their higher risk of death from heart−related issues.