New research published in the Scandinavian Journal of Medicine and Science in Sports has shown that increased sedentary time is associated with increased heart size in adolescents. While increased moderate-to-vigorous physical activity was also associated with increased heart size, the effect of sedentary time on the heart was three times greater.
The study included 530 participants from the UK who were all 17 years old. The participants completed a wide variety of health measures, including fat mass, muscle mass, blood glucose, blood lipid levels, echocardiograph cardiac function and structure measures, and more. Additionally, accelerometers were used to measure sedentary time, light physical activity, and moderate-to-vigorous physical activity among participants.
On average, the participants in the study were sedentary for eight hours per day and participated in moderate-to-vigorous physical activity for 49 minutes per day. Higher amounts of sedentary time and higher amounts of moderate-to vigorous physical activity were both associated with increases in left ventricular mass, but the effects of sedentary time were much larger. Light physical activity was associated with better cardiac function but did not have an effect on heart size.
One of the study’s authors noted that increased cardiac mass significantly increases the risk of cardiovascular disease and death. This study adds to the large body of evidence demonstrating that sedentary time has negative effects on our hearts and our overall health. Besides the direct effects on the heart, sedentary time also increases the risk of developing chronic diseases such as obesity and type 2 diabetes. While moderate-to-vigorous physical activity increases cardiac mass, the effect is offset by the many other heart and health benefits that it provides.
Sources: Scandinavian Journal of Medicine and Science in Sports, Science Daily
