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Muscular Strength
The new guidelines have added resistance training since the ACSM
recognizes the increasing importance of maintaining strength as a health
benefit as we get older. The rationale for the addition of strength training
to the guidelines is a result of a ten year follow-up study on master runners
(along with other studies). Those who continued to train aerobically without
upper body exercise maintained their body's oxygen transporting capacity
over the years, but lost about 4.5 pounds of lean body mass; those who
included strength training in their program maintained their lean body mass
along with their aerobic capacity after 10 years of aging.
The guidelines also show where consistent resistance training helps
maintain bone and muscle mass as we get older. For women, strength training
(along with the aerobic work) may also protect against post menopausal bone
loss and osteoporosis in their later years.
The guidelines recommend that two strength training sessions per week
should be added to your workout schedule. We recommend three sessions a
week during the off-season and two sessions a week for maintenance during
the in-season. The new ACSM guidelines recommend one set of eight to 12
repetitions of eight to 10 strength exercises of your major muscle groups per
session as the minimum requirement. A complete detailed strength training
program will be outlined in a later section of this book. If weights or other
resistance training devices are not available, add calisthenics to your program.
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Cardiovascular Fitness
The new statement, published in 1991, repeats the four recommendations
on duration, intensity, frequency and various modes of aerobic activity, with
slight changes. The duration is now 20 to 60 minutes, versus a minimum of 15
minutes in the past.
Intensity of exercise can be determined by two methods. The first is the
familiar use of target heart rate. The guidelines state that you should aim to
work at 60 to 85 percent of your maximum heart rate (max HR = 220 - your age)
or 50 to 85 percent of your maximal oxygen capacity (determined by doing a
stress test on a bicycle ergometer or treadmill at a medical facility).
Duration is dependent upon the intensity of the activity; for those who like
to work at a lower intensity they should work out longer. Low to moderate
intensity cycling, stepping, walking, or cross-country skiing is best for most
adults, because higher intensity workouts can lead to increased risk of injury
and it is easier to adhere to the exercise routine. Beginners can achieve a
significant training effect from low intensity workouts. If you're already fit
and want to improve, gradually increase your intensity.
The type of activity, once again, should include anything that uses large
muscle groups, and is rhythmical and aerobic in nature, such as cycling or
running. Other activities could include stair climbing, cross-country skiing,
walking, etc. These activities need to be carried out three to five days per week.
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Training Effect
Duration, intensity and frequency of training stimulate the aerobic training
effect. Any training done below the ACSM guidelines will not be sufficient
enough to give you the aerobic training effect. If you are exercising more
than the recommendations, it will not significantly increase the aerobic
training effect, though athletes training for competition need to exercise
more to be competitive. It is important to remember not to over do it; your
body needs adequate recovery from a hard workout.
In general, endurance training for fewer than two days per week at less
than 60 percent of maximal heart rate, for fewer than 20 minutes per day, and
without a well-rounded resistance and flexibility program is inadequate for
developing and maintaining fitness in healthy adults. It is just that simple.
Keep in mind that the ACSM recommendations are guidelines for the
average person, not a champion athlete training for the Olympic Games.
An appropriate warm-up and cool-down, which would also include
flexibility exercises, is also recommended. While many of you will need to
train with more mileage and at a greater intensity to race competitively, the
important factor to remember for most people is that if they follow the ACSM
guidelines of physical activity they will attain increased physical and health
benefits at the lowest risk. Below is a table outlining the guidelines (Table 1.1).
The ACSM guidelines, if followed, can result in permanent lifestyle changes for
most individuals. The good news is that, with the right approach, exercising at
home can and should be pleasant. You can combine strength training, aerobic
exercise and flexibility activities that you enjoy and gain valuable health benefits.
Strength Training
Aerobic Exercise
Stretching
Frequency
2 to 3 times/week
3 to 5 times/week
3 to 6 times/week
Intensity
8-12 reps
60-90% of "easy"
max HR
feeling until fatigue
Stretch Time
20-40 minutes
20-60 minutes
10 minutes
Type
10 exercises
any rhythmical
10 stretches
activity
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Flexibility
To be in total balance it is important to be flexible. While not part of the
ACSM guidelines, flexibility is important for you to perform tasks that require
reaching, twisting and turning your body. Hip flexibility, for example, is
important to preventing lower back pain.
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Exercise and Body Composition
Body composition is an important component of health-related fitness.
Good body composition results from aerobic activity, strength training and
proper diet.
Your everyday caloric balance will determine whether you will gain or lose
weight from day-to-day. Caloric balance refers to the difference between the
calories you take in from food eaten and caloric expenditure or the amount of
energy you put out in daily activities, work or exercise.
Body weight is lost when caloric expenditure exceeds caloric intake or when
caloric intake is less than caloric expenditure. It is a known physiological fact
that one pound of fat is equal to 3500 calories of energy. Though it is
predictable that shifts in caloric balance will be accompanied by changes in
body weight, how your body loses weight varies on the various programs you
may undertake to lose weight. For example, low calorie diets cause a
substantial loss of water and lean body tissue, such as muscle. In contrast,
an exercise-induced negative caloric balance results in a weight loss of
primarily fat stores. If you were to add a resistant training component to
your program, you may also see a slight increase in weight due to a gain in
muscle mass, while an aerobic based program usually results in a
maintenance of muscle mass. While both approaches to weight loss are
effective, aerobic activity is found to be very effective because metabolism
stays sustained for longer periods of time and energy. Expenditure is
greater with activities that use large muscle groups such as walking, cycling,
cross-county skiing, etc.
Follow these guidelines when engaging in a weight loss program that
combines exercise and caloric restriction:
•
Ensure that you are consuming at least 1,200 calories per day in a balanced
diet. You need to consume calories for everyday bodily, healthy functions.
•
You should not exceed more than a 500 to 1,000 calories per day negative
caloric balance, combining both caloric restriction and exercise. This will
result in a gradual weight loss, without a loss of lean body weight (muscle).
You should not lose more than 2 pounds per week on a diet.
IDENTIFYING YOUR BALANCED FITNESS GOALS
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