Many new studies show how a desk job and a generally inactive lifestyle may be destroying your health. Worse, some of these reports suggest even if you attempt to counterbalance the negative effects of sedentary behavior with added exercise you probably will not be very successful. Now, a new study appearing in the journal Mayo Clinic Proceedings finds that fitness may counteract at least some of the harmful effects of sitting too much. “The association between prolonged sedentary time and cardiometabolic biomarkers is markedly less pronounced when taking fitness into account,” concluded the authors.
A team of researchers wanted to investigate whether a relationship exists between sedentary behavior and cardiometabolic risk, while also taking into account general fitness levels. They focused their study on a group of 1,300 men seen at the Cooper Clinic in Dallas, Texas over a period of about 30 years between 1981 and 2012. First, the team examined participants’ responses on a survey to understand each man’s sedentary behaviors, including TV time and time spent in a car. Next, the research team gathered the results of all the participants’ treadmill tests, given each time they arrived at the clinic for examinations. They also collected medical data to determine cardiometabolic biomarkers and metabolic syndrome for each participant. Finally, the researchers compared each participant’s results with a reference group of men spending less than nine hours per week inactive.
What did the researchers discover once they completed their analysis? More sedentary behavior was linked to higher levels of systolic blood pressure, increased levels of total cholesterol and triglycerides, and lower levels of HDL, the "good" cholesterol. The more sedentary men also had higher BMI, waist circumference, and body fat percentage. Yet, the researchers also discovered those men who were more fit showed reduced fat and metabolic measures compared to their less fit counterparts. Another important finding: Sedentary time was not linked to metabolic syndrome, a dangerous cluster of four conditions: high blood pressure, high blood sugar level, excess body fat around the waist, and abnormal cholesterol levels. When these conditions occur together, they increase your risk of heart disease, stroke, and diabetes.
Although confident in these results, the authors warn of the study's limitations. For example, each participant’s level of sedentary behavior was based on his own assessment at the beginning of the study, whereas fitness was objectively measured over 30 years during clinic visits. It is a fact, then, that this study is not definitive, still it provides hope to those of us who earn our livings at a desk job; fighting back by working out and keeping fit does help.
Source: Shuval K, Finley CE, Barlow CE, Gabriel KP, Leonard D, Kohl HW. Sedentary Behavior, Cardiorespiratory Fitness, Physical Activity, and Cardiometabolic Risk in Men: The Cooper Center Longitudinal Study. Mayo Clinic Proceedings. 2014.