Does the intensity of an
exercise program modulate body composition changes?
The International Journal of Sports Medicine;
2006 March, 27(3): 178-81, published research findings
from the Laboratory of Sports Hygiene and Nutrition,
Department of Physical Education and Sport Science,
Aristotle University of Thessaloniki, Thessaloniki,
Greece. The research was conducted by Doctors: Maugios
V., Kayaki M., Christoulas K., Ziogos G., and Petridou
A.
The results of this study
showed that the low intensity group decreased total body
mass by 3.3 kgrms (7.26 lbs) vs. 1.9 kgrms (4.18 lbs)
for the high intensity group. It is important to note;
however, that the low intensity group lost 0.2 kgrms
(.44 lbs) of fat-free mass vs. an increase of 0.5 kgrams
(1.1 lbs) in the high intensity group.
The researchers divided 14
healthy pre-menopausal, untrained women into two groups
which exercised on treadmills at either 45%, or 72% of
V(02max) four times a week for three months, spending
1548 kJ (370 Kcal) per exercise session. No dietary
intervention was applied. Exercise training at 45% of
V(02 max) without dietary restriction produced a higher
weight loss than at 72% of V(02max), but the higher
intensity tended to maintain fat-free mass, possibly, in
part, through the smaller weight loss.
You might also assume that
the Principal of Individuality {refer to the IFPA
Personal Training Manual} may have been in effect due to
the small study size of only 14 women.
You should also be aware
that this research contradicts a previous study
published in the Journal of the American Dietetic
Association; 1995 June, Exercise Intensity Does
Not Effect Body Composition Change in Untrained,
Moderately Overfat Women; 95(6): 661-5. The
study conducted by Grediaqin A, Coday M., Rupp V.,
Vernardot D., and Shern R. used 12 untrained, moderately
overfat, weight-stable women. The women were again
divided into two groups: low-intensity at 50% of
V(02max) or high intensity at 80% of V(02max). They
trained for 12 weeks (four times a week) at a duration
sufficient to expend 300 kcal. The women were asked to
maintain their normal diet and activity. The results
showed that the average weight loss was 0.7 pounds for
the high-intensity group, and 3.3 pounds for the
low-intensity group. Each group lost an identical amount
of fat (5.0 lbs), but the high intensity group gained
more than twice as much fat-free mass (4.3 lbs vs. 1.8
lbs).
You should be well aware
that gaining muscle and losing fat is a primary goal of
anyone training to improve their appearance. While most
of the research over the past decade seems conflicted
whether high or low intensity aerobic exercise is better
for fat loss, almost all the research indicates that
higher intensity aerobic exercise either maintains, or
increases muscle mass. You should also be aware that all
measures of aerobic fitness showed substantial
improvement over the low intensity exercises.
If you would like more
information on this or other exercise related topics
please visit the IFPA
FitBits Archive.
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