Short breaks for walks can counteract the harmful effects of prolonged sitting on the arteries in the legs, suggests a study by US scientists that publishes the online journal Medicine & Science in Sports & Exercise.
A large body of epidemiological evidence suggests that there is a relationship between longer sitting (e.g. when working while sitting) and the risk factors for cardiovascular disease and metabolic disorders, the authors of the article remind. It goes, among others o higher cholesterol or greater waist volume, which is an indicator of heart-threatening abdominal obesity.
There have also been suggestions that short walks may have beneficial effects on cardiovascular health if you interrupt long sitting periods with short walks. However, little research has been done to support this theory.
Researchers at Indiana University in Bloomington (Indiana, USA) studied 12 healthy men between the ages of 20 and 35 who were not obese. In one experiment, they sat in a soft armchair for three hours without moving their legs. In the second, during a three-hour sitting, they had three five-minute breaks for a walk on the treadmill – after 0,5 hours, 1,5 hours. and 2,5 hours
The function of the endothelium of the superficial femoral artery was checked in men at the beginning of the experiment and for one, two and three hours each time. For this purpose, the ultrasound method was used, which assesses the expansion of the artery under the influence of increased blood flow (flow-mediated dilatation – FDM).
The endothelium is the lining of blood vessels. It secretes compounds that regulate, among others vasodilation, coagulation processes and inflammatory processes. Endothelial dysfunction plays an important role in the initial stages of the development of atherosclerosis.
It turned out that during three hours of continuous sitting the endothelial function deteriorated significantly in men – after an hour it was by 50%. weaker. However, short breaks of five minutes for walking (five minutes for each hour of sitting) kept it constant throughout the experience.
“We have shown for the first time that prolonged sitting contributes to endothelial dysfunction, an early indicator of cardiovascular disease,” commented lead author Dr. Saurabh Thosar, who now works at Oregon Health & Science University. In his opinion, the important thing is that taking short breaks for light exercise can prevent this from happening.
As the researcher explains, when we sit the muscles of our legs are relaxed and do not contract to effectively pump blood to the heart. In this situation, blood may remain in the arteries of the legs, which negatively affects the endothelium and, consequently, the ability of the arteries to expand due to greater blood flow. Short breaks for a walk increase skeletal muscle activity and improve blood circulation in the legs. (PAP)