You probably don’t need an expert to tell you that sitting around too much could lead to a sore back or a spare tire. It is widely believed, though, that if you watch your diet and do aerobic exercise at least a few times a week, you can effectively offset your sedentary time. However, research has clearly shown that we cannot counter a pack a day smoking habit simply by jogging. In short, exercise is not a perfect antidote for sitting. Sitting itself probably isn’t any worse than other types of daytime physical inactivity, like lying on the couch watching your favorite sitcom. But for most of us, when we’re awake and not moving, we’re sitting. Most of us have heard that sitting is unhealthy. But many of us also have discounted the warnings, since we spend our lunch hours conscientiously visiting the gym. We consider ourselves sufficiently active. But then we drive back to the office, settle at our desks and sit for the rest of the day. We are, in a phrase adopted by physiologists, ‘‘active couch potatoes.’’ The first law of thermodynamics is the thermodynamic expression of the principle of the conservation of energy and states that when energy is added to a system, it is either stored or used to perform work. Applying this physical law to living entities, such as animals, provides us with the conclusion that when total energy intake is greater than energy expenditure, excess energy will be stored as body fat. The physiological states of overweight and obese are a consequence of cumulative excesses in caloric intake.
Since the 1970s, whereas the average height of American men and women has increased, the average weight has increased 25 pounds. It is tempting to attribute the increase in average weight to changes in population demographics, i.e., “middle age spread,” from aging baby boomers. However, no category of individuals has escaped without weight gain, as reflected in the trend of mean weight for both men and women. Similar trends can be seen in data from children and adolescents. Thus, it is not simply that more people are overweight or obese; the entire population is gaining weight.
So where does sitting for most of the day come into place with all this research? If you spend too much of your time in a chair, your glute muscles will actually forget how to fire. Sort of like gluteal amnesia. Your glutes are your largest muscle group. So if they aren’t functioning properly, you won’t be able to perform basic shapes and probably won’t be able to squat or deadlift as much weight. This will result in you not being able to burn as much fat. Bottom line is, muscles burn calories and your glutes are a powerful furnace for fat burning capabilities.
Weak glutes as well as tight hip flexors cause your pelvis to tilt forward. This puts stress on your lumbar spine, resulting in lower-back pain. It also pushes your belly out, which gives you a protruding gut even if you don't have an ounce of fat. "The changes to your muscles and posture from sitting are so small that you won't notice them at first. But as you reach your 30s, 40s, 50s, and beyond, they'll gradually become a lot harder to fix."
The chair you're sitting in now is likely contributing to the problem. The spine wasn't meant to stay for long periods in a seated position. Generally speaking, the slight S shape of the spine serves us well. If you think about a heavy weight on a C or S, which is going to collapse more easily? When you sit, the lower lumbar curve collapses, turning the spine's natural S-shape into a C, hampering the abdominal and back musculature that support the body. The body is left to slouch, and the lateral and oblique muscles grow weak and unable to support it. This causes problems with other parts of the body. When you're standing, you're bearing weight through the hips, knees, and ankles. When you're sitting, you're bearing all that weight through the pelvis and spine, and it puts the highest pressure on your back discs.
So what's a desk jockey to do? Think in terms of two spectrums of activity. One represents the activities you do that are considered regular exercise. But another denotes the amount of time you spend sitting versus the time you spend on your feet. Every day, make the small choices that will help move you in the right direction on that sitting-versus-standing spectrum. Stand while you're talking on the phone. It all adds up, and it all matters.
Of course, there's a problem with all of this: It kills all our lame excuses for not exercising (no time for the gym, the gym is too far away, a rerun of The Office you haven't seen). Now we have to redefine "workout" to include every waking moment of our days. But there's a big payoff: more of those days to enjoy in the future. So get up off your chair and start non-exercising.
References Levine, J., Schleusner, S., & Jensen, M. (2000). Energy Expenditure of Nonexercise Activity. American Society for Clinical Nutrition, 72(6), 1451-1454. Retrieved from http://ajcn.nutrition.org/content/72/6/1451.full Charts from the American Time Use Survey. (2015, October 26). Retrieved from http://www.bls.gov/tus/charts/ Owen, N., Bauman, A., & Brown, W. (2009). Too Much Sitting: A Novel and Important Predictor of Chronic Disease Risk? British Journal of Sports Medicine, (43), 81-83. doi:10