Do you exercise every day—pounding the pavement, breaking a sweat, raising your heart rate—all in the name of good health? Well, recent studies suggest that when it comes to your risk of premature death, all that physical activity may not matter as much as you think.
Prolonged periods of inactivity—best described as sitting a lot—is unhealthy. Deadly, even. In a survey of some 220,000 adults, those who sat for more than eight hours a day had a 15 percent greater risk of dying within three years than those who sat for fewer than four hours a day, found a March study published in the Archives of Internal Medicine. This risk still held true for those who spent part of their day exercising. The results were worse for those who sat for 11 hours or more a day. They had a 40 percent greater risk of early death compared to those who sat for under four hours. It should be noted, researchers say, that the study didn't prove that sitting caused this risk. It could very well be that people who tend to sit longer are less healthy or have a condition that makes it difficult to walk or stand. Further studies to clarify the relationship between sitting and mortality are needed.
Previous studies, though, have discovered similar results. In 2010, the American Cancer Society released a report in the American Journal of Epidemiology stating that men who sat for six hours or more a day in their leisure time had an overall death rate that was nearly 20 percent higher than men who sat for three hours or less in the 14-year follow-up period. Women who sat for more than six hours a day had a death rate that was almost 40 percent higher. And again, dedicated exercise had no neutralizing effect.
"The human being is designed to move," says James Levine, an endocrinologist and researcher at the Mayo Clinic in Rochester, Minn. "You need to move your body. If you stop your body, idle it—which sitting is—it crumbles on every level." What can result is an increased risk of obesity, high blood pressure, cardiovascular disease, cancer, depression, and possibly Alzheimer's disease, says Levine. A recent study published in the American Journal of Preventive Medicine even observed that women who spent four to seven hours a day sitting showed early symptoms of type 2 diabetes. How can this be, especially for those fitness-minded folks who make an effort to feel the burn?
Imagine if you will, says Levine, a person who works an eight-hour day and goes to the gym three days a week. She wakes up, gets in the car, goes to the office, and sits at her desk all day. Her blood sugar— when sustained at high levels, can lead to multiple health problems like diabetes, strokes, and nerve damage— and her triglycerides—a fat in the blood, which, at elevated levels, can affect heart health— are riding high the whole day due to inactivity. Then she goes to the gym, and for the first time that day, her blood sugar and triglycerides are suppressed.
Now imagine the person who never goes to the gym, but is active for about 15 minutes out of every hour during the day. That person drives down her blood sugar and triglyceride levels over and over and over again. "And that repeated activity throughout the day has a bigger total effect on blood sugar and triglycerides than that one episode at the gym." In the long run, Levine explains, "those sustained pulses of low-grade activity are going to have more of an impact on metabolic parameters than a three-times-a-week visit to the gym." However, Levine says, it should be emphasized that going to the gym certainly can't hurt.
So what does this mean for the typical desk jockey? Studies show that the average American sits for about eight hours a day. "Sitting is like a disease," says Edward Phillips, assistant professor of physical medicine and rehabilitation at Harvard Medical School. "The goal is to avoid prolonged sitting and to add any kind of physical activity to your day." Any movement you can do, even something as simple as tapping your feet, is a start, says Phillips. With that in mind, these suggestions can help if you're strapped to a desk for hours on end: