Exercise prescription in Obesity
Obesity
·
Obesity may be
defined as percentage body fat that increases disease risks.
·
The absolute
percent body fat at which disease risk increases is controversial and this
section will not address the issue of body composition standards for obesity.
·
Rather the focus
is on methods for mordifying the exercise prescription for those who are
excessively fat.
·
An excessive percentage
of body fat (%fat) may be associated with increased risk for development of
hypertension, diabetes, CAD and other chronic diseases.
·
Recent evidence
indicates that “central obesity” (fat deposited primarily in the trunk-
abdominal region) is particularly problematic.
·
In addition,
obesity often carries a negative social stigma and reduce physical working
capacity.
Calorie balance
Calorie
balance refers to the difference between calorie intake (energy equivalent of
food ingested) and caloric expenditure (energy equivalent of biological work
performed)
Factors
such as meal distribution, food sources of calories, absolute caloric intake
and basal metabolic rate may affect total caloric expenditure.
The
first law of Thermodynamics indicates that energy is neither created nor
destroyed but may change form. Therefore body weight is lost when caloric
expenditure exceeds caloric intake (negative balance). Weight is gained when
opposite situation exists.
A-
Caloric intake is less than caloric expenditure= weight loss
B-
Caloric input equals to caloric expenditure= balance
C-
Caloric intake more than caloric expenditure= weight gain
But
fasting and extreme caloric restriction diets cause substantial losses of water
and lean tissue. In contrast, an exercise- induced negative caloric balance
results in weight losses that consist primarily of adipose tissue.
In weight loss programs the major goal
of the exercise prescription is to increase caloric expenditure.
Recommended weight loss programs
For
weight loss program there should be mild caloric restriction with regular
endurance exercise. A desirable weight loss program is one that meets the
following criteria:
1.
Provides intake not lower than 1200 Kcal/d for normal adult so as to
provide a proper blend of food to meet nutritional requirements. (Note: this
requirement may change for children, older individuals, athletes, Etc).
2.
Include foods acceptable to the dieter in terms of sociocultural back ground,
usual habits, taste, costs and ease in acquisition and preparation.
3.
Provides a negative caloric balance (not to exceed 500 to 1000 Kcal/day) resulting
in gradual weight loss without metabolic derangements, such as ketosis. Maximal
weight loss should be 1 Kg/week.
4.
Includes an exercise program that provides a daily caloric expenditure of 300
or more Kcal. For many participants this may be best accomplished with exercise
of low intensity but long duration, such as walking.
5.
Sustained aerobic activities are preferred because they cause the greater total
energy expenditure. For example walking
or jogging, cycling, rowing, stair climbing, walking or jogging through water
that is waist or chest deep can result in a significant energy expenditure.
Exercise session
It
includes
1.
Warm up period
·
Duration is 5-10
min
·
Includes:
walking, slow jogging, light stretching exercises and calisthenics or other
type of muscle conditioning exercises.
·
The intensity and
duration of each of these activities depends on environmental conditions,
functional capacity, symptomatology, and exercise preference of the
participant.
2.
Endurance (aerobic) activity
·
Duration: 15-60
min
·
Includes: aerobic
type activities.
3.
Cool down period
·
Duration: 5-10
minutes
·
Includes:
exercises of low intensities like slower walking or jogging, stretching and in
some cases relaxation activities.
