of skeletal injuries suffered in gymnastics
(Dyment 1991). It is prudent therefore to
encourage gymnasts to consume at least
1200 mg calcium · day–1. There is some evidence
that a higher level of calcium (up to 1500 mg
calcium · day–1) may be even more beneficial in
supporting bone development and reducing
skeletal injury risk, especially for young athletic
females (Carbon 1992). (See Chapter 23 for infor-
mation on calcium.)
Iron
The iron intake of gymnasts was found to be
below the recommended level (15 mg · day–1in
females between 11 and 24 years) in all of the
surveys reviewed (see Table 45.4). This has
numerous implications for the gymnasts’ resis-
tance to disease, but also has implications for
growth, strength, and the ability to concentrate
(Loosli 1993). The current recommendation of
15 mg iron · day–1for adolescents is based on the
10-mg adult male and postmenopausal female
requirement, plus an allowance for menstrual
losses and growth (National Research Council
1989). In fact, linear growth velocity and enlarge-
ment of blood volume during adolescence is
the reason the male recommended intake is
only slightly lower (12 mg · day–1) than that for
females (National Research Council 1989). Since
gymnasts have delayed menarche and a slower
growth velocity than non-gymnasts, it is possible
to conclude that the requirement for iron intake
in gymnasts is lower than that for the general
population. With only limited published data on
the actual haemoglobin, haematocrit, and ferritin
status of gymnasts, it is impossible to fully
understand if current iron intakes match actual
need. There are some data indicating, however,
that a significant number of gymnasts do have
low low serum iron and a high rate of anaemia
(Lindholmet al. 1995).
The typical diet in industrialized nations pro-
vides approximately 6 mg of iron per 4.2 MJ (1000
kcal) of energy (Whitney et al. 1994). Given the
energy intakes seen in past surveys of gymnasts,
it is doubtful that gymnasts would consume
598 sport-specific nutrition
more than 12 mg iron · day–1. With the exception
of the subjects in the Lindholm et al. study (1995),
where gymnasts consumed close to the recom-
mended intake of 14 mg iron · day–1, and where a
number of gymnasts were found to have low
serum iron, all other nutrient intake surveys indi-
cate that gymnasts consume between 6.2 and
12.0 mg iron · day–1. Therefore, even assuming no
growth or menstrual losses of iron, the intake of
iron in gymnasts must be considered inadequate.
A commonly used strategy for reducing
anaemia risk or improving a known low blood
iron level is to supplement gymnasts with a daily
dose of oral iron (Loosli 1993). However, this
strategy may not be the most effective technique
for assuring normal iron status. Recent data
suggest that administration of oral iron every 3–7
days is as good as daily dosing in children, and
produces fewer side-effects (Viteri et al. 1992;
Gross et al. 1994; Stephenson 1995). It also
appears that daily oral iron supplementation
may reduce weight gain and growth velocity by
interfering with normal absorptive mechanisms
(Idjradinataet al. 1994). Therefore, it seems rea-
sonable to suggest that gymnasts consider taking
a weekly or bi-weekly supplement of iron and
consume more iron-rich foods to reduce the
risk of developing iron-deficiency anaemia. (See
Chapter 24 for information on iron.)Nutritionally related problems
studied in gymnasts
Female athlete triad
This triad of disorders represents eating disor-
ders (anorexia nervosa, anorexia athletica,
bulimia, and other restrictive eating behaviours),
amenorrhoea (both primary and secondary), and
early development of osteoporosis (Smith 1996).
The degree to which the female athlete triadoccurs
in gymnastics remains unclear because a
symptom of eating disorders is denial of the
disease, and surveys typically rely on the respon-
dent to provide clear and accurate information
(Benardot et al. 1994). There are additional weak-
nesses in the reliability of the Eating Disorder