Physical Activity

Exercise 2

Physical Activity & Weight Loss

Expert panel concluded that physical activity alone, mostly done in the form of aerobic exercise, resulted in about a 2.4 kilogram reduction in body weight. Another studies from resistance exercise, say that the effect on body weight was modest and the amount of weight loss was less than one kilogram in most studies.

However, resistance exercise, when done at the right threshold, may actually cause an increase in fat-free mass. So, the actual weight is not changing. Fat goes down, muscle goes up.

The importance of lifestyle physical activity may come from some observational data. Some have suggested that the energy imbalance that we experience that has caused the weight gain to occur and thus obesity to occur may be as little as 10 to 100 calories per day, suggesting that if we could just increase energy expenditure by 100 calories a day, we might actually prevent weight gain.

What's probably more important is to look at the combination of how physical activity and diet combined contribute to body weight management. The first thing to consider are the short-term changes in body weight that result from the combination of diet and physical activity.


What we show here is that the greatest weight loss occurs in individuals who are engaging in both diet and exercise. The next largest weight loss comes from individuals who are engaging in diet alone. Thus, when exercise is added to diet, it appears that the increase in weight loss is about two kilograms.

Studies of physical activity show that physical activity is typically a significant predictor of long term weight loss maintenance in individuals who have lost weight and were previously overweight or obese.

In addition, we tend to find that there is a dose effect in that greater amounts of activity, lead to greater long-term benefits.

A consistent finding right now is that individuals who engage in about 250 to 300 minutes per week or the equivalent of about 2,000 calories of exercise per week have the greatest potential to maintain weight loss long term. The American College of Sports Medicine recommended the following.

  • First, Adults should participate in at least 150 minutes per week of moderate-intensity physical activity. It was believed that this might prevent significant weight. This amount of activity has also been shown to reduce chronic disease risk factors.
  • There is likely a dose effect of physical activity on body weight, the goal might be to get individuals to 250 to 300 minutes a week in order to have the best success at maintaining weight loss long term.

In conclusion, moderate-intensity physical activity of somewhere between 150 and 250 minutes per week or between 1,200 and 2,000 calories per week will provide a modest weight loss of up to about 3% of initial body weight. While modest, this might have a significant impact on chronic disease risk factors, such as blood pressure, or possibly lipids, blood sugar levels, or insulin. It appears that the more you do, the greater the effect will be. However, to maximize weight loss, it appears that physical activity needs to be combined with a moderate, calorie-restricted diet where energy intake is reduced.


Strategies for Improving Physical Activity

As we begin to think about how we can actually become more physically active, one of the things that we need to consider is, what is our motivation for being physically active to begin with? It's possible that our motivation might be to improve fitness, to improve health, to improve appearance, to improve energy, or for weight loss. Understanding why we are interested in becoming more physically active, will help us to motivate us and maintain that motivation.

However, changing activity does not come without a cost. We have to make the investment. It doesn't happen on its own. Thus, it's important to understand what we are willing to do, in order to cause this activity increase. For example, are we willing to prioritize physical activity? Are we willing to get up earlier to exercise, to be physically active. Are we willing to watch less television? Are we willing to seek out opportunities? Saying that you want to exercise, or be more physically active, and your willingness to actually get out and be more physically active are two very different things.

This is where motivation comes in. As one starts to think about becoming more physically active, an important thing to consider are problem solving strategies.

If we are currently not active, that means that we have a barrier. Thus, before we can recommend to us what we need to do to be more physically active, it will be important for us to first understand what the barrier is or the problem is. Once we have identified the problem, then we can start to focus on strategies to overcoming the problem. For example, if you live in a cold environment, and that's the barrier, we can work on strategies that would allow us to not have to be exercising in that cold environment. However, these strategies need to be realistic. For example, telling a person to get up earlier in the morning, when in fact the person has no desire to get up earlier in the morning is probably not going to be an effective strategy.

Once we have identified realistic strategies, it's then important to identify one strategy that we're going to try. If it's unsuccessful, we need to pick other strategies. The barrier that one might face in the summertime when it's extremely hot, may be a very different barrier than the barrier that one faces in the wintertime when it's extremely cold. Thus, this is a dynamic process and we have to be ready to identify the barriers that get in the way, and strategies that are realistic to implement, in order to maintain the physical activity that we desire.

Therefore, barrier identification is closely linked to the problem solving strategies that we need in order to come up with a solution that will actually work long term. The factor to consider, is how behaviors chain together. We need to identify the weak links in the behavior chain, in order to make the most effective changes in our behavior related to physical activity.

Probably the most common barrier to physical activity is the perceived lack of time. It is important to emphasize that in many cases it's a perceived lack of time rather than a real lack of time. It's really how we prioritize our time and whether activity is prioritized,. Just like all the other things that go into our day. Thus, for us to overcome this perception of lack of time, there are a number of strategies that we might want to consider.

  • First, we need to make it a priority. That means that we have to make it as important as any other health behavior that you do. Every day you're instructed to brush your teeth, shower, and do other health behaviors. Activity is something you should do every day.
  • Get at least ten minutes of activity every day. As you work towards trying to get to a goal of at least 30 minutes of activity every day.
  • Emphasize what you can do versus what you can't do. While you might have wanted to go and exercise for 30 or 60 minutes today, the time just may not permit it. Is there ten, 15, or even 20 minutes that might work for you on that given day?
  • You can then make up that difference on a different day during the week. Developing a pattern of regular activity, where you do some activity every day, is probably critical to developing a healthy lifestyle around physical activity.
  • One thing that's really been shown to be effective, is multiple shorter bouts of activity. A lot of individuals have difficulty finding 30 or 60 minutes of activity continuously. However, if you break your activity up into smaller bouts, as little as ten minutes at a time, and just do a number of those over the course of the day. That's going to be equal to doing them all at one time. So in this case, taking a ten minute walk at your lunch hour. Taking a 10 minute walk at your coffee break. Taking a 10 minute walk right after dinner at night, might be great strategies as one begins to develop a more physically active lifestyle.

Physical activity is a key health behavior. It's not effective to simply tell someone to be physically active, or believe it's important to be physically active. There are barriers that get in the way of one being physically active, thus we need to identify effective strategies that may involve problem solving techniques. To identify the things that get in the way, as well as strategies that we can use to overcome the barriers that we face.

Only through implementation of effective strategies will we be able to build an effective, physically active lifestyle