Even modest exercise reduces the risk of heart failure

Numerous past studies have shown a link between levels of physical activity and the risk of cardiovascular disease (CVD). Despite the fact that mortality from CVD has decreased in recent decades, it remains a leading contributor to the global burden of disease and physical activity is an important, modifiable risk factor that can be implemented in a person’s lifestyle without too much difficulty. However, most of the evidence in studies to date has relied on self-reported levels of physical activity, which may be prone to various sources of bias and inaccuracy.

A new study by researchers based at the University of Glasgow is the first to use device-measured levels of physical exercise to investigate the association between activity and risk of heart failure. During the years 2013–2015, participants were randomly invited to take part in the study if they had already given their data to the U.K. Biobank, a large research database in the United Kingdom that enrolled and collected health information on 500,000 adults between 2006 and 2010. 

The 94,739 adults that were selected in this way had an average age of 56, were predominantly female (57 percent) and white (97 percent). None of them had been diagnosed with heart failure or had had a heart attack at the time of their enrolment in this study. Each participant wore a wrist accelerometer for seven consecutive days, 24 hours per day, to measure the intensity and duration of physical activity. Subsequent data on incidence of heart attacks in participants was collected through linked hospital and death records.

The results of the analysis showed that, during the follow-up period (median duration of 6.1 years after the physical activity measurement was conducted), adults who had logged 150–300 minutes of moderate physical activity in one week had a 63 percent lower risk of heart failure, compared to participants who engaged in minimal to no physical activity. Adults who had performed 75–150 minutes of vigorous physical activity in one week were estimated to have a 66 percent lower risk of heart failure. These estimated risk reductions are after taking into account factors such as age, sex, ethnicity, education, socioeconomic conditions, smoking, alcohol intake and diet.

Physical activity is such an important aspect of keeping ourselves healthy that the US Department of Health and Human Services issued Physical Activity Guidelines for Americans in 2018. They recommended that adults engage in at least 150–300 min/wk of moderate physical activity or 75–150 min/wk of vigorous physical activity, or an equivalent combination of both intensities. The American Heart Association followed suit, recommending at least 150 min/wk of moderate-intensity aerobic exercise or at least 75 min/wk of vigorous aerobic exercise, or a combination of both.

“There are many potential ways that regular physical activity may reduce the risk of developing heart failure,” said Frederick K. Ho, Ph.D., co-lead author of the study and a lecturer in public health at the University of Glasgow. “For example, physical activity helps prevent weight gain and related cardiometabolic conditions, such as high blood pressure and Type 2 diabetes, all of which are risk factors for heart failure. Regular physical exercise may also strengthen the heart muscle which, in turn, may prevent heart failure from developing.”

Heart failure is a chronic, progressive condition that develops when the heart is not capable of pumping sufficient blood to keep up with the body’s needs for blood and oxygen, and it can result in fatigue and difficulty breathing. Heart failure affects more than 6 million adults in the United States, according to the American Heart Association, and more than 86,000 Americans died of heart failure in 2019. 

According to Ho, the study results suggest that going above and beyond the current AHA recommendations for moderate activity may provide even greater protection against heart failure. “We found that moderate physical activity has the potential increased cardiovascular risk benefits up until 500 min/wk, as appropriate for each individual,” he said. However, participants who performed more than 150 min/wk of vigorous physical activity showed did not show a further reduction in risk of heart failure. 

“These findings indicate that every physical movement counts. A leisurely, 10-minute walk is better than sitting and no physical activity. And, if possible, try to walk a little faster, which increases the intensity and potential benefits of exercise,” Ho said.

People whose risk of heart failure is high, due to their being overweight or obese, having high blood pressure or elevated glucose or cholesterol, may be particularly likely to benefit from increasing their physical activity, according to Ho and colleagues.

“Health care professionals may suggest more physical activity based on a patient’s current lifestyle and health status,” Ho said. “Generally, moderate physical activity is easier to incorporate into daily routines, and it’s generally safer. Vigorous physical activity is sometimes the most time-efficient and may be more suitable for busy people. However, caution is advised for all when beginning a new physical activity regimen to prevent injuries or acute adverse events (such as a heart attack in a formerly sedentary person initiating a vigorous exercise program).”

Although the results of the study suggest a link between reduced risk of heart failure and boosting the duration, frequency and intensity of exercise, this is an observational study and so it cannot prove a cause-and-effect link. Further experimentation would be required for this. In addition, because participants were overwhelmingly white, further studies would be needed to confirm that these results also apply to people from diverse backgrounds.

“Our findings add to the overwhelming body of other evidence, suggesting that maintaining even a modest amount of regular physical activity can help prevent a range of chronic conditions from developing, including heart failure,” said senior study author Professor Naveed Sattar.

The research is published in Circulation, the flagship journal of the American Heart Association

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By Alison Bosman, Earth.com Staff Writer