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Strength
training has long been recommended to normal and underweight
individuals as a means of increasing muscular mass, enhancing
fitness, and vitality. Indeed, organizations such as the American
College of Sports Medicine (1995) have advocated strength
training consisting of single sets of 8 to 12 repetitions
on 8 to 10 exercises per workout for healthy persons. However,
it is not as clear whether strength training should be recommended
for overweight persons whose goal is weight (more specifically
fat) loss rather than the acquisition of lean muscle mass.
In this article we will describe the potential role that a
rationally derived program of strength training can play in
weight loss efforts, and outline some broad recommendations
to enhance its effectiveness.
In order to lose body fat, you must create an energy deficit
(i.e., expend more calories than your body needs to function).
Unfortunately, when you create such a caloric deficit you
do not lose just body fat. That is, the body takes energy
from body tissue indiscriminately. In fact, any diet produces
not only fat loss, but lean tissue loss as well. A recent
analysis by Ballor and Poehlman (1994) indicated that an average
of 28% of the weight lost among dieters who do not exercise
is actually fat-free mass (i.e., lean tissue) compared to
13% among dieters who performed primarily aerobic exercise.
Indeed, if the caloric deficit is severe enough (e.g., very
low calorie "fasting" diets) even organ tissue and
bone is lost. Moreover, since dieting is an unnatural act,
the body begins to adapt by reducing resting metabolic rate
(RMR).
This means that you have to create progressively greater caloric
deficits to continue to lose body fat at a consistent rate.
Given this, the primary goal for utilizing strength training
in conjunction with weight reduction activities is to preserve
fat-free mass while losing body fat. The preservation of fat-free
mass also serves to keep the metabolic rate as high as possible
so that fat loss can be promoted even with a relatively modest
level of caloric restriction. In addition, strength training
may be a useful strategy for maintaining the fat loss (i.e.,
keeping the weight off) once the person has reached their
goal.
That is, developing as little as one pound of muscle tissue
after dieting will allow a moderately active person to consume
an additional 50-100 calories per day. In fact, adding three
pounds of muscle increases metabolic rate by about 7%. The
bottom line is that gaining lean muscle is highly desirable
because muscle is metabolically active (i.e., it needs a modest
amount of calories to survive) while fat is not.
When fitness professionals develop exercise programs for overweight
persons, they sometimes do not advocate strength training.
One major reason for this is that many overweight persons
are reluctant to engage in strenuous anaerobic activity. It
is far easier to convince the overweight person to engage
in low intensity aerobic activity ("to burn fat")
than to workout with weights in a high intensity fashion.
Indeed, it is quite common for us to be told by an overweight
person seeking treatment "I want to lose weight, not
gain it." Again, they are confusing weight loss with
fat loss. Moreover, it is very unlikely to gain a significant
amount of muscular bodyweight when one is on a strict diet.
Individuals who endorse this view need to be rationally convinced
that, in the long run, a program of high intensity strength
training will be of substantial benefit to them. It will not
only help them lose fat more efficiently during dieting, but
it will also help them to maintain the fat loss once they
return to a less restricted "maintenance" diet.
Let us look at how overweight adults can use a “High Intensity
Training” (HIT) approach to maximize the short- and long-term
effectiveness of their weight loss/weight control efforts.
Note that our broad suggestions will need to be modified somewhat
given the unique circumstances of a given overweight individual.
Intensity
Intensity is the name of the game in strength training. You
have to work hard enough to set the growth machinery into
motion. However, with the overweight individual you cannot
simply launch right into training to momentary positive failure.
It is possible, even likely, that the person has no history
of intense physical activity of any kind. As such, you need
to slowly and gradually increase the intensity of the workouts
(perhaps over several weeks) until the person is physically
and mentally capable of working an exercise with the required
intensity.
Remember, training to positive failure is a skill that takes
time to learn. You must also consider that, with a caloric
deficit, the person is not likely to be able to train at the
same level of intensity as someone who is not dieting. So
you want the person to train as hard as they can, but within
the context of a deficient caloric intake. We would not suggest
intensity generating techniques (e.g., static contractions,
negatives etc.) while the person is dieting. These techniques
make such a profound inroad on recovery that they could be
detrimental to someone who is dieting. It should go without
saying but any overweight individual (irrespective of whether
or not they have existing health problems) should consult
a physician before engaging in this, or any other, type of
training.
Brief
The anaerobic workout for an overweight individual should
only be as long as required to stimulate the growth, or in
this case, the maintenance of fat-free mass. Most often, individuals
that are overweight mention that time constraints make it
difficult to participate in a regular strength training routine
or that they have no interest in spending hours in a gym.
Making workouts short and intense should provide necessary
stimulation of muscles without producing disinterest or boredom.
We suggest single work sets of 3 to 5 multi-joint exercises
which focus on the larger muscle groups (legs, hips, back).
Weights can usually be lifted using approximately 60 to 80%
of their initial 1RM and slowly progressing from there. Workouts
should be conducted at a rather brisk pace and should be kept
to less than 30 minutes. We would not necessarily discourage
low intensity aerobic activity after the weight training,
but if the weight training was of sufficient intensity, it
is unlikely that the overweight person would want, or be capable
of performing, a great deal of aerobic exercise.
Infrequent
Overweight persons are usually making major life changes to
fit in strength training. Interestingly, a lack of time is
the most cited excuse for not exercising among overweight
and non-overweight people.
Indeed, one reason many overweight people are anti-strength
training is the belief (propagated in the popular muscle media)
that you must train very long and frequently (1-2 hours, up
to 6 days a week) in order to make progress. The brevity and
relative infrequency of HIT training may be very appealing
to the overweight trainee. We would suggest training two to
three times a week initially in order to develop the motor
skill necessary to adequately and safely perform the movements.
As the intensity increases, the frequency of training should
be reduced to ensure proper rest and recovery. It is likely
that the a dieting trainee will require even more time between
workouts to adequately recover as a reduced calorie deficit
diet is likely to delay repair and growth.
Safety
As mentioned before, these individuals may have major health
risks that will be of concern to the fitness trainer. HIT,
being a high intensity low-force training protocol, is very
safe, provided proper exercise technique is used. Make sure
these individuals acquire the skill to perform each exercise
properly before having them train alone.
Stressing slow controlled movements with good form will lessen
the chance of injury. Obviously, the use of machines would
be preferred because they require less skill to execute the
movement.
Apart from general instruction regarding proper exercise technique,
a great deal of emphasis should be placed upon educating the
overweight person with respect to muscular soreness, correct
breathing, and any other factor which may be relevant to their
training. It has been our experience that many overweight
persons are particularly sensitive to, and sometimes fearful
of, the sensations that go along with intense exercise (e.g.,
heavy breathing, elevated heart rate etc.). Any information
that can alleviate fear in this regard would be of great benefit
to the overweight trainee.
Conclusion
The benefits of HIT are not restricted to those who simply
want to increase their strength and muscular body weight.
In conjunction with reduced caloric intake, overweight persons
can use the HIT approach to attempt to maintain their existing
muscle mass. By preserving fat-free mass, their dieting effort
will likely be more time-limited and effective. It needs to
be made clear to the overweight person that the goal is fat
loss, not weight loss per se. Indeed, the ability to maintain
their fat loss will be enhanced greatly by using HIT principles
to increase their muscular bulk once the period of caloric
restriction has ended. In sum, brief, intense and infrequent
HIT training can be a valuable component of a comprehensive
fat loss regimen.
References
American College of Sports Medicine (1995). Guidelines for
exercise testing and prescription (5th edition). Baltimore,
MD: Williams & Wilkins. Ballor, D.L., & Poehlman,
E.T. (1994). Exercise training enhances fat-free mass preservation
during diet-induced weight loss: a meta-analytic finding.
International Journal of Obesity, 18, 35-40.
This
article edited and reprinted by permission of
I.A.R.T.
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