According to a new study by researchers from the American Cancer Society, The Cooper Institute, and the University of Texas, there is an association between prolonged sedentary time and obesity and blood markers associated with cardiovascular disease is markedly less pronounced when taking fitness into account.
Kerem Shuval, Ph.D., of the American Cancer Society, examined the association of sedentary behavior, physical activity, and fitness to obesity and metabolic biomarkers among 1304 men seen at the Cooper Clinic in Dallas, Texas between 1981 and 2012. Sedentary time was composed of self-reported television viewing time and time spent in a car self-reported on a 1982 survey. Fitness was determined by a treadmill test during the medical examination at clinic visits.
The study showed that more sedentary time was significantly associated with higher levels of systolic blood pressure, and total cholesterol and triglycerides, as well as lower levels of HDL, the "good" cholesterol.
It was also associated with BMI, waist circumference, and body fat percentage. But when researchers controlled for fitness, they found prolonged sedentary time was only significantly associated with a higher triglyceride/HDL cholesterol ratio (an indicator of insulin resistance). Sedentary time was not associated with metabolic syndrome (a clustering of risk factors). In comparison, higher fitness levels were associated with reduced adiposity and metabolic measures.
The study was published in the journal Mayo Clinic Proceedings.