For centuries, we’ve known that exercise does a body good, even if the underlying scientific explanations were unknown or unclear. In the past decade, however, we’ve made huge strides in deciphering the extraordinary relationship between physical fitness and total health. This has been made possible by the latest technology and recent novel collaborations among various fields of science and medicine. The latest research has allowed us to measure, analyze, and understand biologically what happens when we flex our muscles, take a brisk walk, join a fitness class, pedal a bicycle, pick up heavy boxes, or train for an athletic event.
We have been in constant pursuit of survival since the birth of humankind. In fact, our genetic makeup requires and expects our bodies to be physically challenged via regular exercise. But as we are well aware, only a small percentage of us cater to our body’s need to move frequently. Modern technology has its benefits, but it also has its drawbacks when it facilitates sitting all day. Most everything we need can be obtained without having to exert much effort, much less get off our butts. We were not designed to thrive in a sitting position, and that fact has played into the rates of chronic illnesses that can be associated with being sedentary, such as diabetes and heart disease (“sitting diseases”).
Nearly 80 percent of adult Americans do not get the recommended amounts of exercise each week. A 2012 study led by Harvard researchers and published in The Lancet determined that inactivity is tied to more than 5 million deaths worldwide—more than those caused by smoking! A survey of nearly thirty thousand women in the United States done the following year found that those who sat nine or more hours a day were more likely to be depressed than those who sat fewer than six hours a day. Some of the biological reasoning makes common sense: your circulation is reduced when you’re sitting down, and as a result the flow of feel-good hormones to your brain is also reduced.
This is partly why the headlines in the past couple of years have declared inactivity, especially prolonged sitting, as the “new smoking.” You may even have read articles suggesting that no matter how fit you are, if you sit for most of the day, you face a higher risk of numerous health challenges and premature death. So even if you exercise hard for an ambitious hour or more a day, you’re still putting your health at risk if you’re mostly stationary the rest of the day. And we all know how easy this can be if you spend your days driving in your car, working at a desk, and interacting with lots of screens, from computers and tablets to cell phones and televisions. Sitting too much despite exercise is akin to smoking despite exercise.
Being in a seated position is not in itself harmful. But sitting for prolonged periods over and over again entails biological effects that negatively influence things like blood fats, blood sugar balance, resting blood pressure, and many hormones, some of which help control your metabolism, appetite, and the volume of food you eat. The body essentially turns off at the metabolic activity level when it’s idle for a long time. As your circulation slows down, your body uses less of your blood sugar and burns less fat, both of which increase your risk of heart disease and diabetes—two of our leading killers today. New science is showing the impact that being immobile has on certain genes. For example, one pivotal gene that’s been identified is called lipid phosphate phosphatase, or LPP1. We think this gene helps to keep our cardiovascular system healthy by preventing dangerous blood clotting and inflammation. But it’s significantly suppressed when the body is idle for a few hours, so it can’t do its job to maintain cardio health. Even exercise won’t impact this gene if the muscles have been inactive most of the day. In other words, LPP1 is apparently sensitive to sitting but resistant to exercise.
So it’s a foregone conclusion: a physically active lifestyle is vital for good health as well as important for increasing life expectancy. What probably surprised some of the researchers is that the people who were overweight (but not obese) and engaged in physical activity lived longer than those of normal weight who were inactive.
Other research has also shown this to be true: it’s better to be physically fit and overweight than to be of normal weight and sedentary. Indeed, movement matters. Movement over time matters most.
Note that physical activity encompasses a lot of different kinds of movement. It is important to generally keep active during your day with walking, dancing, gardening, hiking, swimming, cycling, household chores, games, sports and community activities. Using a “standing desk” or sitting on a “stability ball” enhances movement. Multiple effects happen simultaneously when the body is on the go, even if it’s just walking around while talking on the phone, taking the stairs instead of the elevator, or simply making a point to get up every hour for a five-minute stroll, stretch, or jog in place. All of these movements will have positive biological effects to offset the poison of excessive sitting.
Reference: David B. Agus. “The Lucky Years” January 2016
“Lack of activity destroys the good condition of every human being, while movement and methodical physical exercise save it and preserve it.”
Paul R. Block, MD, FACP, FCCP