According to a study presented at ESC Congress 2023, hours of inactivity during childhood could be laying the groundwork for heart attacks and strokes later in life.

Even in people with normal weights and blood pressure, the study found that sedentary time accumulated from childhood to young adulthood was linked to cardiac damage.

“All those hours of screen time in young people add up to a heavier heart, which we know from studies in adults raises the likelihood of heart attack and stroke,” said study author Dr Andrew Agbaje of the University of Eastern Finland, Kuopio, Finland. “Children and teenagers need to move more to protect their long-term health.”

This was the first study to look into the connection between young people's sedentary time as measured by smartwatches and later-life heart disease.

It was carried out as a part of the Children of the 1990s project, one of the largest cohorts with lifestyle assessments starting at birth and beginning in 1990/1991.

3 Children aged 11 used an activity tracker-equipped smartwatch for seven days. This happened once again at age 15 and once more at age 24.

At 17 and 24 years of age, the weight of the heart's left ventricle was measured by echocardiogram, a form of ultrasound examination, and expressed as grammes per cubic metre of height (g/m2.7).

After adjusting for variables that could affect the relationship, such as age, sex, blood pressure, body fat, smoking, physical activity, and socioeconomic status, the researchers examined the relationship between sedentary time between the ages of 11 and 24 and heart measurements between the ages of 17 and 24.

From 11 to 24 years of age, every additional minute spent sitting was linked to a 0.004 g/m2.7 rise in left ventricular mass between 17 and 24 years of age.

This translates to a daily rise of 0.7 g/m2.7 or a 3-gramme increase in left ventricular mass between echocardiogram measurements at the average height gain when multiplied by the additional 169 minutes of inactivity.

A similar rise in left ventricular mass (1 g/m2.7) during a seven-year period was linked to a two-fold greater risk of heart disease, stroke, and mortality in adults, according to a prior study.

Dr Agbaje said that children were sedentary for more than six hours a day, increasing by nearly three hours a day by the time they reached young adulthood.

Our study indicates that the accumulation of inactive time is related to heart damage regardless of body weight and blood pressure.

Parents should encourage children and teenagers to move more by taking them out for a walk and limiting time spent on social media and video games. As Martin Luther King Jr. once said, run if you can't fly. If you can't run, walk. If you can't walk, crawl. But by all means, keep moving.