Hypertensive and cardiac patients should be more careful to exercise in the cold

In the last week, the city of São Paulo registered the coldest dawn for the month of May in 18 years, according to the CGE (Centre for the Management of Climatic Emergencies of the City of São Paulo).

At times like this, it’s hard to get out of bed to hit the gym before work or go for a run in the late afternoon. But people with cardiovascular problems who practice physical activity need to face yet another difficulty during this period. Experts warn of increased risk of heart disease.

“The cold makes the heart beat faster, blood pressure rises, the vessels of the legs contract and there is a greater release of hormones, such as adrenaline. All this increases cardiovascular risk”, reports cardiologist Eduardo Pesaro, scientific advisor. of Socesp (São Paulo State Cardiology Society).

According to the ergometrist Luiz Augusto Riani Costa, from the High Excellence Diagnostics group of the Dasa group, in São Paulo, these events are related to the body’s adaptation to low temperature.

It’s just that, in the cold, the body feels the thermoregulatory need to warm up. This involves the release of adrenaline to intensify metabolic activity and the constriction of blood vessels to reduce heat loss through the skin. These two phenomena cause the cardiovascular work to increase, overloading the heart and increasing pressure.

“If the arterial system has fragile areas, they can rupture, leading to a stroke. [AVC]. In addition, as the arteries are ‘tight’, if there are obstructive plaques, this reduces the flow of blood, leading to a heart attack, thrombosis or an ischemic stroke”, says the doctor.

The possibility of this happening is much higher in people with risk factors for cardiovascular events, such as obesity, diabetes, hypertension, high cholesterol and family history.

And there is also the influence of respiratory diseases, which are more common at this time. “Studies show that these infections worsen the situation of the heart, increasing the cardiac danger”, adds Pesaro.

The cardiologist from Socesp says that this relationship is already widely known in the medical community, especially in countries with cold or temperate climates. According to the AHA (American Heart Association), in winter the possibility of a heart attack grows by up to 30%. However, the relevance of these problems in hot countries such as Brazil was not very clear until recently.

Therefore, in 2018, Pesaro, who also works at Hospital Israelita Albert Einstein, in São Paulo, participated in a study with other specialists from the hospital, USP (University of São Paulo) and NYU (University of New York), in United States, to verify if the same was happening in the capital of São Paulo.

The researchers collected data on 76,000 hospitalizations for heart failure and 54,000 for acute myocardial infarction in public hospitals in the city between 2008 and 2015. The result showed that in winter, the occurrences of failure were 30% higher than in summer. Infarction patients were 16% higher.

But what does all this have to do with exercise? The cardiologist explains that, as the practice of physical activity is a situation in which the body is led to stress and the heart naturally needs to work harder, the danger ends up increasing for people with a high probability of suffering heart problems.

How cardiac patients should protect themselves

However, this does not mean that this population should stop exercising when the temperature on the thermometer drops, just take some precautions. The Socesp specialist gives simple tips: dress warmly and try to sweat your shirt during the hottest hours of the day or in closed places, such as the gym.

An important reminder is that cities in Brazil are not so well prepared to face low temperatures. “Often, in tropical countries, there is a certain neglect of winter. The clothes are not so powerful, the buildings do not have heating and the windows and doors are not properly sealed”, laments Pesaro. If you do activities indoors, you need to keep an eye on this.

Reducing training intensity is also an interesting strategy. Costa, the ergometrist at the Dasa group, says that when you suddenly stop exercising – something very common in the cold – the body suffers a significant deterioration in its general physical condition, which puts life in danger.

“If I stop training, this effort increases a lot because I’m deconditioned. Then, the heart accelerates much more, the pressure shoots up and there will be a greater cardiac overload for something that is everyday, being able to anticipate a cardiovascular event”, alerts the ergometrist. So instead of stopping, prefer to decrease the intensity.

Of course, all these situations become more recurrent among those who are affected by this type of disease and do not control it. So, being up to date with medications and medical evaluation is also part of care.

“If your blood pressure is unregulated, your medication is not being taken correctly and you are not attending routine appointments, obviously any exercise is dangerous, not only in winter”, concludes Pesaro.