Do you sit all day, but then hit the gym a few times a week? The gym sessions may not help as much as you would like. A study has confirmed that people who are inactive for hours each day have an increased risk of diabetes and heart disease even if they get regular exercise.
The association between being inactive and risk factors for diabetes and cardiovascular disease was strong regardless of age, gender, weight and whether participants exercised regularly, the study found. However, the study was not designed to prove that an inactive lifestyle causes diabetes or cardiovascular disease.
In the study, researchers from Albert Einstein College of Medicine and Montefiore Health Systems in the Bronx analyzed data collected from 12,000 people in Chicago, Miami, San Diego, and the Bronx in New York. The data was collected from 2008 to 2011. The participants were asked to wear activity monitors for 16 hours a day for one week. The monitors showed that the participants were inactive for about 12 hours daily.
Then, the researchers divided the participants into four groups based on the amount of time they were inactive. They found that the least active group had 6% lower levels of high density lipoprotein (HDL) cholesterol than the most active group. HDL lipoprotein is the "good cholesterol" that helps reduce the risk for heart disease. The least active group also had levels of triglycerides that were 16% higher than the most active group. Triglycerides can increase the risk of coronary artery disease. This group also had higher blood sugar levels and less ability to process the hormone insulin, which indicate a risk of diabetes.
Even when people met physical activity guidelines that call for at least 150 minutes a week of moderate intensity aerobic exercise or 75 minutes of vigorous exercise, more hours of sedentary time were still linked to an elevated risk of diabetes and heart disease.
These results are more evidence that a healthy lifestyle is not just getting exercise but also limiting inactivity. But there are two limitations to the study. The activity monitors that were used could not distinguish between sitting and standing. Also, the study looked at risk factors, and not at actual outcomes such as heart attack or stroke.