Fitness May Counteract Cons of Sedentary Life

Cardiovascular disease and ailments linked to inactivity may improve with physical activity

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) A sedentary lifestyle may not seem dangerous, but it can put good health in peril. Some physical activity, however, may remedy its ill effects.

Research has shown that prolonged hours of inactivity may be a real killer. Too much sitting may lead to obesity, Type 2 diabetes, heart disease, some cancers and premature death. A new study has found that physical activity may protect against the harms of sedentary living.

"Exercise regularly to help ward off heart disease."

This study was led by Kerem Shuval, PhD, a cancer researcher at the American Cancer Society and with the Division of Epidemiology at University of Texas School of Public Health in Dallas.

The investigation involved 1,304 men who visited the Cooper Clinic in Dallas between 1981 and 2012. These participants, who had an average age of 46, reported their own sedentary behavior, providing information on how much TV they watched and time they spent driving.

During clinic visits, researchers evaluated patient fitness through treadmill tests.

Dr. Shuval and colleagues found that more time spent sitting was significantly related to higher levels of systolic blood pressure, as well as total cholesterol and triglycerides (a type of fat found in the blood).

Inactivity was also linked with lower levels of HDL, or "good" cholesterol, and increased body mass index, waist circumference and body fat percentage.

When researchers factored in the effects of fitness, they observed that sedentary time did not appear to be tied to metabolic syndrome. "Metabolic" refers to the biochemical processes related to normal body function, and metabolic syndrome is a clustering of conditions that usually include increased blood pressure, a high blood sugar level, excess body fat around the waist and abnormal cholesterol levels. These conditions elevate the risk of heart disease, stroke and diabetes.

Cholesterol levels, however, were the exception. The triglyceride/HDL cholesterol ratio remained high even after accounting for fitness.

For example, the authors wrote that a reduction in total cholesterol was associated with increased physical activity. Being sedentary 22 hours or more weekly, however, decreased the effects of physical activity on total cholesterol.

Overall, increased physical activity was tied to reductions in body fat and improved metabolic measures.

Based on their findings, Dr. Shuval and collaborators encouraged higher levels of fitness through following physical activity guidelines in order to decrease metabolic risk. They added, however, that further investigation is needed on how decreasing sedentary time may affect metabolic syndrome.

The study was published online July 14 in Mayo Clinic Proceedings. The researchers reported no conflicts of interest.

Review Date: 
July 18, 2014
Last Updated:
July 21, 2014