NUTRITION IN SPORT

(Martin Jones) #1

height and weight in these populations. This is
due to the notable exceptions in body-fat trends
seen in the more competitive groups analysed.
These more competitive gymnasts have higher
weights, but lower body fat, indicating that the
more elite gymnasts have more muscle mass per
unit weight. The least competitive of the groups
analysed are the tallest, weigh the most, and
have the highest body fats for their age groups.
This finding is in agreement with a study of
young highly elite gymnasts, who were in the
25th percentile for height/age and weight/age,
but in the 75th percentile for arm-muscle circum-
ference and arm-muscle area (Benardot &
Czerwinski 1991).
It was pointed out in a study by Grediagin et al.
(1995) that exercise of different intensities is not
related to differential changes in body fat if the
total energy burned is equivalent. In this study, it
was determined that change in body fat was
equivalent in high- and low-intensity activity,
but low-intensity exercise (aerobic) caused a
greater change in weight because the high-
intensity activity was better able to maintain (or
increase) lean body mass. Therefore, seeing low
body fat levels and high lean body mass in highly
active gymnasts involved in high-intensity
anaerobic activity is not unexpected.
A standard technique used by gymnasts to
attain (or retain) what they perceive to be an ideal
body for gymnastics is restrained eating. There
are several questions about whether restrained
eating is, ultimately, a good strategy for achiev-
ing this end since we have adaptive mechanisms
that tend to stabilize tissue composition, even in
the presence of altered energy intake (Flatt 1987;


602 sport-specific nutrition


Saltzman & Roberts 1995). A study by Benardot
(1996) demonstrated this point. In evaluating
energy balance by monitoring within-day energy
imbalances on national team gymnasts, he found
that the size of the largest energy deficit within a
day was significantly correlated (r=0.583;P=
0.004) to body-fat percentage, and the number of
energy deficits within a day that were greater
than 300 kcal explained a sufficient amount of
variance in body-fat percentage that it could be
predicted (see section on energy intake, above).
In addition, total energy intake had a significant
negative correlation with body-fat percentage
(r=0.418;P=0.038). That is, the lower the energy
intake, the higher the body-fat percentage. This
adaptive response of lower energy expenditure
and higher body-fat storage with inadequate
energy intake may drive gymnasts to continually
eat less to achieve the desired body profile. Sadly,
this restrained eating pattern may also be the
stimulus to the eventual development of disor-
dered eating and related problems that are so
often seen in gymnasts.

Growth retardation

Gymnasts are significantly smaller than non-
gymnasts of the same age and they appear to be
missing the distinct growth spurt typically seen
in adolescence (Lindholm et al. 1994). However, it
remains unclear whether this shorter stature is
due to a self-selection in the sport, which may
attract and retain small individuals, or if there is
a real stunting of growth that occurs as a result of
participation in gymnastics. It has been reported
that gymnasts who train more than 18 h · week–1

Table 45.6Meta-analysis: Pearson correlation coefficients of means.


Age (years) Body fat (%) Height (cm) Weight (kg)

Age (years) 1.000 0.712* 0.720* 0.829*
Body fat (%) 0.712* 1.000 0.505 0.520
Height (cm) 0.720* 0.505 1.000 0.961*
Weight (kg) 0.829* 0.520 0.961* 1.000


  • Correlation is significant at the 0.01 level (2-tailed).

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