Taking small breaks from sitting down such as standing for phone calls or walking to see colleagues might trim office workers’ waistlines and help their heart and metabolic health, a study suggests.
The more breaks people took, the smaller their waists and the lower the levels of a blood marker linked to inflammation, the research, published today by the European Heart Journal, showed.
The study is the first to look at the effects of remaining sedentary on the heart health of a broad swath of the population. The research tried to capture how much people moved as part of their daily routines, the lead author, Genevieve Healy, a research fellow at the University of Queensland, Australia, said in an interview yesterday.
"What we found was the more sedentary people were, the more sitting and the more reclining people did, the worse off they were in terms of cardio-metabolic function and inflammation, such as waist circumference, blood fats, lower levels of good cholesterol and protein inflammation markers," Healy said.
The researchers drew on data from almost 4,800 volunteers outfitted with devices that tracked their activity for seven days as part of the U.S. National Health and Nutrition Examination Survey. The average age of the participants was 46.5 years, and half were men. The participants wore their tracking devices, called accelerometers, for 14.6 hours a day, of which 8.44 hours were inactive and about a third of an hour was used to exercise.
The researchers measured the size of the participants’ waists, their blood pressure, cholesterol levels and the concentration of a protein linked to inflammation called C-reactive protein.
The longer people were inactive, the higher their levels of blood fats and markers of insulin resistance. The more breaks they took, even those as short as a minute, the smaller their waists were.
The most active quarter had waists that were 4.1 centimeters (1.6 inches) smaller than the least active quarter, Healy said.
When the study broke down the results by ethnicity and gender, they found that Mexican-Americans were the most active but had the highest levels of blood fats. Women were more likely to be sedentary but took more breaks and had a more favorable cardio-metabolic profile.
While the exact biological mechanism is not clear, the researchers believe that contracting large posture muscles "flushes out the bad stuff," Healy said.
Small breaks cannot replace regular exercise, such as walks at lunch time, Healy cautioned. "One little break can’t cure the world."