As I noted in my first post about exercise and weight loss, most weight loss programs recommend that you work on both sides of the equation, eat fewer calories and burn more off.  Now that we’ve covered some topics about implementing an exercise plan, I wanted to close with some key points to consider as you start to increase your activity:

• Depending on your age and health, you may need to check with your physician before you start an exercise program.
• Plan to gradually increase your activity, especially if you usually don’t exercise.
• As you exercise more, you may notice an increased appetite.  Avoid eating more calories by drinking more water or choosing healthy, low-calorie foods.
• Recommendations for an exercise plan of moderate intensity include cardio exercises 3 to 5 days a week and weight training 2 days a week.
• Moderate intensity is the equivalent of a brisk walk.
• Your age & health may prevent your engaging in too vigorous an exercise program.

I hope these last few posts about exercise and weight loss help you to improve your health and weight.

For Your Health – Dr. Bob

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 the risks of physical activity? As
you might expect, physically active adults do experience a higher rate of leisure
time and sports related injuries than those who are less active. Despite this,
those that engage in moderate intensity aerobic activity have a similar overall
injury rate when compared to the more sedentary people. It seems that the
more active individuals may have more activity related injuries, but the
nonsport and nonleisure injuries are less. The reverse is true for their more
sedentary counterparts. As the intensity level increases, so does the risk of
injuries. The risk of cardiac arrest or heart attack is low for healthy adults
at the moderate intensity levels, but it increases as the intensity level
increases especially for those who exercise infrequently. This underscores the
importance of getting a medical clearance from one’s physician before starting
any exercise program. It is recommended that, “Symptomatic persons or those
with any cardiovascular disease, diabetes, other active chronic disease, or any
medical concern, should consult a physician prior to any substantive increase
in physical activity, particularly vigorous intensity activity.” (1)

In the next post we’ll revisit the relationship between MET levels and weight loss.

For Your Health – Dr. Bob

Footnotes: 

(1) W. L. Haskell, et al. Circulation. 2007;116:1089; originally published online Aug. 1, 2007

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.