There is a common myth that if you
stop exercising, your muscle will turn to fat, but this is simply not true.
That should be good news for those of you who might have fallen off the
exercise wagon. Even better news for those who train with weights comes from
recent research at the University of Missouri.
Researchers noted that both
resistance training and weight loss—independent of each other—are known to help
improve both abdominal obesity as well as insulin resistance, both risk factors
for diabetes and heart disease. At the same time most overweight and obese
persons who lose weight tend to gain at least some of that weight back. Could
resistance training help those who regain some weight hang on to some of the
benefits of weight loss?
They recruited nine people between
the ages of 34 and 40 with an average body mass index of 33.8 (clinically
obese). The participants were non-smokers and were otherwise fairly healthy.
For the first phase of the study the participants lost weight by engaging in
aerobic exercise (such as using a treadmill, stationary bike or elliptical
trainer) and reducing their caloric intake with the help of nutrition
counselling. The goal for this phase, which lasted about 11 weeks, was for each
participant to lose about 1.5 to 2 pounds per week.
In the second phase the
participants stopped doing aerobic exercise and switched to only resistance
training, using free weights as well as exercise machines. They also increased
their caloric intake to regain about half the weight they had lost.
At the start of the study, at the
end of the weight loss period and again at the end of the resistance training
period, the participants had their cholesterol levels checked, as well as blood
pressure, BMI and waist to hip ratio. In addition, the researchers also
measured overall lean body mass and body fat percentage while also measuring
how much of that body fat was in the abdomen.
Their results are quite
interesting. As you might expect, losing weight by doing aerobic exercise and
reducing calories improved the participants’ BMI, while their overall body fat
percentages and their abdominal fat declined. Their total cholesterol and LDL
cholesterol (the bad cholesterol) also fell, as did their insulin levels.
When they regained some of the
weight, however, their cholesterol levels, both total and LDL (good
cholesterol), returned to about the same as they were at the start of the
study. On the other hand, they kept about half of the improvements they had
made in waist circumference, overall body fat percentage and abdominal fat
while becoming physically stronger.
This is a very small study but the
results are in line with the results of other studies. Since the participants
in this study only regained some of the body fat they had lost, you might say
that resistance training helped fat turn into muscle. Now there’s a good reason
to pick up some weights.