“That which is used – develops. That which is not used wastes away.” Hippocrates Circa 450 BC

Weight loss. That, and maintaining one’s weight, are the main reasons many of us exercise. While there are other reasons to exercise (it improves health, gives us energy and it’s also fun), we as a society are fascinated by our weight.

First off, I should say that it’s not excess weight that a lot of us are concerned about, it’s excess fat. It’s just that it’s easy to weigh ourselves, but we need to recognize that weight also includes bone and muscle as well. For most people, these two components make up the majority of our body’s weight.

Having excess body fat increases our risk for a number of conditions such as certain cancers, heart disease and diabetes, not to mention the negative stigma many in society project towards those with excess body fat.

Let’s be realistic though, losing excess fat in the long-term is hard. It’s extremely hard. While we live in a society that views people with excess body fat as lazy, that’s really not the case. Our society promotes a lifestyle conducive to eating excess foods and not being physically active. Some people have termed this as the obesogenic environment, and it works against people trying to eat healthy and be active.

Even in spite of the environment we live in, if we exercise we should be able to lose weight, right? Well, yes and no. Any type of activity, whether exercise or just walking down the stairs to the kitchen burns calories. This is important as the amount of fat we have on our body is related to the amount of calories we take in (through food) and burn off (through our metabolism and activity). However, it isn’t quite as simple as it sounds.

For many adults, we need somewhere between 1500 and 2000 calories to keep us alive at rest. This is our basal metabolic rate. So even if we were inactive all day, we would still need to eat just to keep us alive. As mentioned previously, the recommended guideline for activity is 30 or more minutes per day on most days of the week. If one was to do this minimally recommended activity by brisk walking, you would only expend approximately 500 calories in a week, or about 100 calories per 30 minutes of walking. That’s about a medium apple or banana worth’s of calories per day, while a pound of fat is about 3500 calories. So while there are numerous benefits from even doing this little amount of activity, it will be hard to lose weight from it.

Another thing that can make it hard for losing weight when people exercise is what’s called compensation. This can be in two types; compensating by being less active the rest of the day, or compensating by eating more that day. In some instances, we may ‘reward’ ourselves with food for doing exercise, and thereby counteracting the energy used to exercise by eating more.

Lastly, and particular to weight bearing activities like walking, running (or any activity in which one is running like soccer, tennis, etc.) and to some extent cycling, the less we weigh, the easier it is to move our bodies. As we are successful with losing body fat our weight will decrease. This is good but what it now means is that for those weight bearing activities, we are actually burning less calories during that activity than before. For example, if a person’s regular exercise consists of a two mile walking route, and let’s say that over the span of a few weeks that person loses two pounds of weight and weighs less. As a result of weighing less, walking that same two miles at the same speed will actually be less effort and therefore less calories will be used. The opposite is true in that if that same person is to carry a 20 pound backpack while walking, it will result in a greater effort and more calories used. This means that as a person loses weight, he/she will need to become more active to lose more weight.

So even though exercise itself is not very effective in losing weight, exercise still has a very important role within a weight loss regimen. While the cornerstone for weight loss is alterations in diet, when people lose weight by diet alone, this commonly includes a loss of muscle mass as well as fat. This loss in muscle mass is detrimental to our health. The addition of exercise to a weight-loss diet is that it helps to prevent any loss in muscle mass and ensures that whatever weight that is lost comes from body fat.

Overall, the best way to lose body fat is through a combination of both diet and exercise, and remember, that even without any loss in weight, exercising and being active has so many other benefits to reduce your risk for diabetes, cancer, heart disease, osteoporosis, stress and improve your mental well-being.

In the next blog I will discuss how to be active later in life.

This is Part 8 in a series of blog posts entitled Being Active While Living an Active Life.