A hard workout may seem like a good way to blow off steam after a fight with your partner or a disappointing day at work. But it might be smart to avoid going all-out in the heat of the moment: A new study suggests that combining heavy physical exertion with a negative emotional state could put you at increased risk for a heart attack.
The research found that either factor was linked to heart attacks on its own, but that the association was strongest in people who experienced them both shortly before their symptoms started. That was true across all groups in the study—including people who had preexisting risk factors and those who didn’t.
“Previous studies have explored these heart attack triggers; however, they had fewer participants or were completed in one country,” says lead author Andrew Smyth, MD, PhD, a researcher at McMaster University in Canada and at the HRB Clinical Research Facility in Ireland. “This is the first study to represent so many regions of the world, including the majority of the world's major ethnic groups.”
The study, which was published Monday in the journal Circulation, analyzed data from more than 12,000 heart-attack survivors, average age of 58, across 52 countries. After their heart attacks, the participants were given a questionnaire that asked if they’d engaged in heavy physical exertion, and if they had been angry or emotionally upset, in the hour before their symptoms began. They were also asked about the same hour on the day before their heart attacks, as well.
When the researchers compared people’s day-of and day-before responses, they found that heavy physical exertion was associated with a more than two-fold risk of suffering a heart attack. The same was true for being angry or emotionally upset.
But the even bigger danger seemed to come from a combination of the two potential triggers. Being angry or upset while engaging in heavy exertion more than tripled the risk of having a heart attack, compared with someone experiencing neither.
This was true regardless of participants’ smoking status, body mass index, blood pressure levels, and other health problems, and regardless of whether they were taking heart-related medicines such as aspirin, statins, or beta blockers.
“We did not find any significant differences between those with and without these risk factors,” Smyth told RealSimple.com. “Therefore, our findings apply to a wide population.” The authors found no significant difference between age groups—under 45, 45 to 65, or over 65—or gender, either.
The researchers also performed what’s known as a sensitivity analysis, comparing the main study participants with a control group who hadn’t had heart attacks. (The control group was asked whether they’d experienced heavy exertion and/or anger or upset moods in the last 24 hours.) “Interestingly, by taking this approach we found very similar results,” says Smyth, “demonstrating that our results are robust.”
Smyth says that extreme emotional and physical triggers seem to have similar effects on the body.
“Both can raise blood pressure and heart rate, changing the flow of blood through blood vessels and reducing blood supply to the heart,” he says. “This is particularly important in blood vessels already narrowed by plaque, which could block the flow of blood leading to a heart attack.”
Overall, of course, exercise is good for the heart—and high-intensity exercise has benefits that can’t be matched with light physical activity alone. Smyth says his study is not meant to discourage hard workouts, but he does provide a few words of caution.
“We would recommend that a person who is angry or upset who wants to exercise to blow off steam not go beyond their normal routine to extremes of activity,” he says. That advice applies to everyone, he adds, including healthy people with no history of heart problems.
In fact, the study authors recommend avoiding extremes of either triggering event—physical exertion or being angry or upset. “Practically speaking, people cannot eliminate exposure to these, as they may be unpredictable and part of day-to-day variation in life,” Smyth wrote in a email. “But we would encourage people to minimize exposure.”
Barry J. Jacobs, PsyD, director of behavioral sciences at the Crozer-Keystone Family Medicine Residency Program in Springfield, Pennsylvania, says the new study—which he was not involved in—provides evidence of the important link between mind and body.
"Excess anger, under the wrong conditions, can cause a life-threatening heart attack,” he said in a press release from the American Heart Association. “All of us should practice mental wellness and avoid losing our temper to extremes.”
Jacobs agrees that people—especially those who are already at higher-than-average risk for heart attacks—should try their best to avoid very emotional situations. “One way many cope with the emotional ups and downs of a health condition is through peer support, talking with others who are facing similar challenges can be very helpful in better managing your own emotions,” he suggests.
The study authors acknowledge that their study was only able to show an association, not a cause-and-effect relationship. They also say that, because the potential triggers were self-defined, opinions of what constituted heavy exertion, anger, or being upset surely varied from person to person.
But Smyth says that’s OK, because these things are very subjective; for example, someone who's usually very sedentary may consider a certain activity to be strenuous, while a fitter and more active person sees it as much more leisurely.
What may matter most, he says, is what’s extreme or out-of-the-ordinary for you—and that you avoid combining those extremes whenever possible.
This article originally appeared on RealSimple.com.