As I wrote here, here , here and here, the science of sedentary behavior is the current variation of exercise science that is confounding experts.
Here, a NY Times fitness and wellness writer summarizes a recent study that demonstrates what I reported in this blog post way back when: that is, when people do go to the gym or park to exercise, they often counterbalance that positive behavior by minimizing movement elsewhere throughout the day.
This concept derived initially from observations on participants in weight loss programs. First, when people cut back on calories, based on predictions that are based on basal metabolic rates (BMR) and estimates of 3500 calories equalling a pound of fat, they tend to not lose weight at the rate or amount expected. Many factors contribute to this finding; one of the more stunning, however, was that many people move less when they have fewer calories in their diets.
Thus, they compensate/substitute inactivity for caloric reduction. 
Other studies that included an exercise component for weight loss or disease management also anticipated more dramatic results than they were seeing. This generated a ‘fear’ that, novice exercisers either ate more to compensate for the extra calories they were burning, or moved less elsewhere in their day or week to minimize the benefits of the study’s program.
Not long ago, some researchers settled on the phrase ‘substitution’ instead of ‘compensation’. Thus, when provided guidelines or even supervised exercise programs for managing heart disease, diabetes, or weight, people, even if they participate in the programs consistently, still find ways to move less throughout their normal day. This substitution of sedentariness for normal low-intensity movement may indeed counter any benefits the organized exercise were supposed to provide.
The question the average reader should be asking, however, is not whether such substitution is bad enough to make exercise – regimented movement – meaningless or useless. The question is, how do I justify for myself the time and effort I put into exercise even if I am going to substitute more calories or less movement elsewhere?
You see, a bout of exercise has its own value, provides its own set of benefits, separate and distinct from substituted behaviors. If it’s only about burning calories to lose weight, then exercise may be delusional if you’re going to sub in some extra servings of wine, cheese or cake. But that would, in my opinion, be a poor rationale for exercise.
Exercise – cardio, strength or flexibility – yields so many more benefits than just weight control or even blood pressure control.
Psychologically, it is calming, stress-reducing, sometimes enlightening, as when you’re trying to solve a problem and your brain works under the radar while the body sweats the details.
Physically, it moves body parts, enough to maintain some muscle and maybe bone mass, to maintain or even gain strength, or simply to retain tonus and elasticity to facilitate normal, pain-free (or at least pain-less) motion.
Cognitively, by assisting blood flow to the brain or making neural demands on it to learn new movements, it may slow age-related declines in reflexes, problem solving, memory and/or higher-order executive functions.
Organismically, it moves blood through organs, especially the heart, kidneys and gut, that help them perform their duties better. From men’s erectile function to women’s menstrual cycle pains, from bladders to rectums, being physically fit has been shown to confer benefits over and above, and below, body composition and even cardiac health.
Exercise, as the ACSM is proud to say, is medicine. And even if you sit more throughout the days you do exercise, even if you eat a little more or a little worse on the days you exercise, you are still getting many benefits that the research has clearly demonstrated.
So don’t despair substitutions; don’t beat yourself up for being less than perfect when it comes to incorporating an exercise program into your overall lifestyle. Just because the weight does not come off as expected, or the butt doesn’t look like J-Lo’s, or the doctor still wants you to continue taking a statin does not mean it’s not good for you.
In fact, think of it this way: if you weren’t doing your regimented exercises, do you really think you’d get any thinner, have any firmer a butt or see your cholesterol drop by doing what you’ve been doing, sedentarily?
I think not.
