How does all this relate to losing weight? The key point to remember is that the MET level associated with an activity does not directly equate to the number of calories expended. The weight of the individual performing the activity will determine how many calories are expended at a given MET level of activity. So, a person who is 220 lbs. performing the same activity for the same amount of time as someone weighing 110 lbs. will burn twice as many calories as the lighter weight individual. Since it is true that no matter what a person’s weight, to lose 1 pound they need to have a weekly caloric deficit of 3,500 calories, the heavier person will lose the 1 pound faster! This also means that as they continue to lose weight, they will not lose weight as quickly with the same amount of exercise! To continue the rate of weight loss they must increase the amount of energy expended by increasing the number of METs or the duration of the activity. These are important points to bear in mind as you progress towards your weight loss goals.

So from this we can see that a progressive exercise program can help us lose weight throughout the weight loss and maintenance phases. But it can do more than that. Perhaps its greatest value is to prevent chronic medical conditions and help treat many conditions. All great reasons to exercise!

In my next post I’ll review some of the important things to remember about starting your exercise program.

For Your Health – Dr. Bob

What about exercise for older people?  An article, entitled “Physical Activity and Public Health in Older Adults: Recommendation From the American College of Sports Medicine and the American Heart Association.” (1) published in Circulation in August 2007 provides recommendations for physical activity in those over 65 or those who have chronic medical conditions, low fitness levels or physical limitations. It is similar to that for adults but also takes into account the older adult’s aerobic fitness, and recommends activities that maintain or increase flexibility and those that improve balance to prevent falls. Such an individual may progress more slowly and walking at a slow pace may be the equivalent of moderate intensity activity for them. Their muscle training should consist of more repetitions (10-15) than for their younger counterparts. This suggests that the weights should be light enough to enable them to perform 10-15 repetitions before their muscles fatigue. The flexibility training may take the form of at least 10 minutes of stretching of major muscle groups with 10-30 seconds of static stretch and 3-4 repetitions for each stretch. These should be done on the days when aerobic and strength training are done.

The point is made that exercise programs in these people must take into account the treatment aspects of exercise for many of the chronic conditions such as, hypertension, coronary heart disease, type 2 diabetes and elevated cholesterol to name a few. Fortunately, in many instances the therapeutic recommendations are similar to the preventive ones. However with certain conditions the emphasis may change. For example someone with osteoporosis would follow the preventive recommendation of aerobic, muscle strengthening, and balance activities, but they would emphasize weight-bearing activities and possibly high impact activities, such as jumping if tolerated. Of note, not every aerobic activity is weight-bearing. Swimming and cycling are not and have little, if any, preventive benefit for osteoporosis even though they are aerobic activities. They do benefit the cardiovascular and respiratory systems of the body.

The recommendation also emphasizes the fact that “There is substantial evidence that older adults who do less activity than recommended still achieve some health benefits…For example, lower risks of cardiovascular disease have been observed with just 45-75 minutes of walking per week.” (2)

In the next post I’ll talk about some of the risks of exercise.

For Your Health – Dr. Bob

Footnotes:
(1) M. E. Nelson, et al. Circulation. 2007;116:1094-1105; originally published online Aug. 1, 2007

(2) Ibid. pg. 1101

The next logical question is what kinds of activity are recommended? The
answer lies in a newly published article in Circulation
which is the Journal of the American Heart Association, entitled, “Physical
Activity and Public Health: Update Recommendation for Adults From the American
College of Sports Medicine and the American Heart Association.”(1)
For all healthy adults aged 18 to 65 years of age the recommendation is a
minimum of moderate intensity aerobic (endurance) physical activity for a
minimum of 30 minutes on five days each week or vigorous intensity aerobic
physical activity for a minimum of 20 minutes on three days each week. A common
way to estimate energy expenditure for a given activity and understand what is
meant by these intensity designations is to use the concept of METs or
metabolic equivalents. When someone is sitting quietly, they expend 1 MET. The
moderate intensity activities expend from 3.0 to 6.0 METs and the vigorous
activities exceed 6 METs. In terms of METs, the minimum goal is to expend 450
to 750 METs per week in moderate intensity activities, vigorous intensity
activities or a combination of the two. A person can meet the minimum by a
combination of moderate and vigorous intensity activity. Moderate intensity
activity is generally equal to a brisk walk and noticeably increases the
heart rate. Vigorous intensity aerobic activity causes rapid breathing and a
substantial increase in the heart rate. Jogging is one example of vigorous
intensity activity. The table below gives some examples of common activities
and classifies them in these categories.

So how does exercise relate to weight loss? Well we know that to lose weight you need to take in fewer calories as food than you burn through exercise and other activities. Exercise can help you burn more calories than without it, so weight loss should be helped by increased activity. While that’s true, it’s a bit more complex than that with real implications for losing weight. Before we discuss that we need to better understand some concepts that a discussion of exercise and prevention can best illustrate.

Beyond its effect on weight loss, one of the major benefits of exercise is in prevention. A recent study (1) in women underscores these key relationships. This study built upon the large Nurses’ Health Study. This study looked at data on over 88,000 women ages 39 to 59 from 1980 through 2000. None of these women had heart disease or cancer when the study began. Over the 20 years of the study, the women reported their diet, physical activity level and waist circumference every 2 years. The results found that women who were inactive and obese had nearly 3.5 times the risk of having coronary heart disease than those who were active and lean. The lead researcher, Dr. Frank B. Hu, noted, “A high level of physical activity did not eliminate the risk of coronary heart disease with obesity, and leanness did not counteract the increased coronary heart disease risk associated with inactivity.”

In the next post I’ll talk about some recommendations for exercise in healthy adults.

For Your Health – Dr. Bob

Footnotes: (1) Circulation. 2006;113:499-506

In an earlier post, Obesity & Health, I included this formula:

Formula For Weight Loss: Calories Out (Activity) > Calories In (Food Eaten)

In earlier posts we talked about the Nutrition side of this equation.  Now we’ll consider the activity part.  It makes sense that increasing your activity level can help you lose weight since you burn more calories.  Incorporating an exercise plan in your daily routine consists of making behavior changes and should be approached in the same way.

• Choose an activity that you’d like to try.  A tool for determining Activity Calories on my website InsightsForHealth.com can help you learn how many calories you can burn with different activities.
• Decide on your exercise goals and when you intend to reach them.  Goals:
  • Time of day you’ll exercise
  • Duration of each exercise session
  • How often you’ll exercise.
  • Identify the date you will begin to exercise.
  • Identify possible obstacles to starting your exercise program and ways to overcome them.
  • If there is any question about the safety of your proposed exercise program due to your age or health status, check with your physician before you begin.

I’ll talk more about your exercise plan in upcoming posts.  They will cover the following topics as you get ready to introduce an exercise program into your routine:

1. Making Your Exercise Plan
2. Benefits of Exercise
3. Recent Recommendations for Healthy Adults
4. Those Older Than 65 Or with Chronic Conditions
5. Risks of Exercise
6. Back to Exercise And Weight Loss
7. Points to Remember About Starting Your Exercise Plan

For Your Health – Dr. Bob