Aerobic exercise for women has many health benefits,
but it has only been in the last few years that research into weight
training has documented many of the same health improvements.
Weight training is associated with lower resting heart
rates, reductions in blood pressure, improved cholesterol profiles,
increased glucose tolerance, and reduced intra-abdominal fat. One
study showed similar decreases in fat mass following 25 weeks of
resistance training for both men and women over age 60, but women in the
study lost a larger percentage of their fat from intra-abdominal and
subcutaneous abdominal fat stores than men did. This is
significant: After menopause, women tend to store more fat in the
abdominal area, which increases their risk of disease. Since
intra-abdominal fat is associated with lifestyle diseases such as heart
disease, hypertension and diabetes, using weight training to target this
type of fat will help lower a women's overall risk for disease.
Traditionally, women are resistant to weight training
programs because of a number of myths, including the fear of getting
bigger and looking masculine. As a result, they flock to
aerobic programs. People of all ages and genders need to be educated on
the benefits of a weight training program so that any concerns,
questions, and myths can be addressed. Once these concerns have
been answered the numerous benefits of weight training can be realized
and incorporated into regular exercise routines.
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Common Myths
About Weight Training |
Most myths, if not all, are based on misinformation and can easily be
eliminated through education. Some of the more common myths and concerns
are as follows:
“I don’t want to get ‘big’ or less feminine.”
Many women are concerned that if they begin a weight
lifting program they will develop large, unsightly “manly” muscles. Perhaps the greatest area of difference between the
sexes is in hormonal concentrations: women have a 15 to 20 times lower
concentration of testosterone than men do. Women need to
understand that they simply do not have the necessary quantities of
testosterone (in addition to less muscle tissue) to build muscles
(hypertrophy) like a
man.
“My friend started lifting weights and she gained
weight”
Of course she did! Muscle tissue weighs more, by volume,
than fat tissue. (A pound of fat takes up 1.1 liters of space; a pound
of muscle takes up only .9 liters.) A pound of fat occupies 18%
more space than a pound of muscle. Most women will see a decrease in
body circumference due to the decrease in fat mass that accompanies the
increase in muscle mass but, because muscle weighs more than fat, they
may indeed see an increase in their body weight, even though girth
measurements may shrink.
Helpful Tip: stay away from the scale. A daily or
weekly “weigh-in” can sabotage a lifting routine. (It has been said that
when an American woman steps on the scale she is weighing her
self-esteem : )
“Will my muscle turn to fat if I stop training?”
Muscle and fat are two entirely different types of
tissue and one can never become the other. When a women stops weight
training, daily caloric expenditure decreases and muscles atrophy. Over
time this will reduce her resting metabolic rate (RMR). If calorie
intake is not lowered when she stops weight training, she will gain fat.
“Since women don’t hypertrophy (get big) can I gain
strength?”
Strength and hypertrophy, though related, are different
concepts. Strength is neurological: Weight lifting trains the nervous
system to recruit and fire motor neurons more efficiently while reducing
muscle inhibition; this allows for greater tension and the ability to
move a resistive force more efficiently. Women gain strength
at the same rate as men: During the first 8 weeks of a strength
training program the dramatic increases a woman sees in her strength are
due to neurological improvement, not hypertrophy.
Hypertrophy (getting big) is physiological and is due to
increasing the size of the individual muscle fibers. Since women do not
have the same muscle mass, or, accordingly, number of fibers, as men do,
they do not build mass the way men do.. At some point,
hypertrophy tends to plateau, however women continue to gain strength
through neuromuscular and hormonal channels.
Some of the physiological and psychological benefits of
strength training follows include:
• Preservation of Function
Aging is associated with an increased risk of disease
and a loss of function. Most of this functional loss can be attributed
to reductions in muscular strength and endurance, as well as to
reductions in flexibility. After age 50, strength is lost at the rate of
12% to 14% per decade, and muscle atrophy occurs at the rate of 6% per
decade with a preferential loss of fast twitch (strength) muscle fibers. One study of women over the age of 70 found that 74% could not lift a 10
pound weight; another showed that for some inactive older women, getting
out of their chair just once resulted in a 100% recruitment of the
quadriceps muscles. Strength training is vital for these women:
Strength gains of more than 30%, and muscle mass increases of 12%, have
been documented within two months of beginning a lifting program. This
means that two decades of strength and muscle loss can be reversed
within two months of strength training!
It is important to point out that aerobic exercise alone
does not reverse age-related decreases in muscle mass and strength: A
study that compared 70 year old resistance trained athletes to both 28
year olds and age-matched sedentary controls found that only the
resistance trained older adults had cross sectional areas identical to
the 28-year-olds. Weight training improves both strength and flexibility
for women, helping to maintain function later in life.
• Preservation of bone mass
Osteoporosis is a concern for many post-menopausal
American women. Risk factors for osteoporosis include advancing age,
menopause, low estrogen levels, family history, race, heredity, low
dietary calcium, low body weight, smoking and inactivity. Women
are particularly vulnerable to dramatic bone loss during the first
decade following menopause: Anywhere from 15% to 30% of bone mass can be
lost during this critical period. This bone loss is
permanent. To date, research shows that exercise and medications do not
regress osteoporosis; they only slow down the loss of bone mass.
Increased muscular strength is positively correlated to
increased bone mineral density. Weight-bearing exercise, which includes
weight training, should be performed throughout life in order to achieve
and maintain maximum bone density and reduce the risk of fracture to the
wrist, spine and hip in the event of a fall. The strength
training protocol that is recommended for preservation of bone mass
includes completing three to four sets of 6-10 reps 2 to 3 days per
week. In addition, this protocol should be used while doing multi-joint
free weight exercises such as squats, lunges, deadlifts, push-ups, dips
and chin-ups.
• Weight control
Most, American women list “weight control” as a primary
reason for exercising, which is why they flock to the cardio room.
However, there are
several potential advantages in terms of caloric expenditure when
performing weight training versus moderate aerobic exercise.
Moderate aerobic exercise, such as walking on the
treadmill, or taking a group exercise class, has a metabolic cost of 5-7
calories per minute for a woman of average fitness. Moderate to vigorous
strength training has a metabolic cost of 5-8 calories per minute. This
means that women will experience a similar caloric burn with either
activity, but with a major difference: Moderate aerobic activity
primarily recruits slow twitch muscle fibers, so when the exercise
session stops metabolic rate returns to normal very quickly. Weight
training is performed at a higher intensity, and recruits both slow
twitch and fast twitch muscle fibers, so the metabolic rate stays
elevated longer to replace liver and muscle glycogen stores, as well as
muscle triglycerides, for protein synthesis. This allows for increased
fat oxidation and increased caloric expenditure not only during exercise
but also after exercise.
Maintaining and increasing lean body mass is important
to women for weight control, function and preservation of bone mass,
since metabolic rate is highly correlated with fat free mass (muscle,
bone and organ tissue). Muscle mass accounts for about 22% of the
metabolic rate. On average,
following 8 weeks of weight training, beginners can increase lean mass
by 2 pounds and decrease fat mass by over 4 pounds. Metabolic rate
increases, on average, by 6.8% following 8-12 weeks of weight training.
Women who performed resistance training for 12 weeks while on very low
calorie diets (800 kcals) maintained their fat free mass and increased
their RMR. Women who performed aerobic exercise while on very low
calorie diets lost significant lean mass and also
experienced a decrease in metabolic rate.
