NUTRITION IN SPORT

(Martin Jones) #1

drate and lowest fat intake is seen in national
team gymnasts, and the lowest carbohydrate and
highest fat is seen in college male gymnasts. An
increase in fat and protein intake has been pro-
posed recently as a means of increasing athletic
performance (Sears 1995), but there is little evi-
dence that such a diet would actually improve
athletic performance (Coleman 1996). There is
good evidence that increasing dietary fat intake
may not influence energy metabolism to the
degree that increasing carbohydrate intake does
(Schutzet al. 1989). Therefore, increasing fat
intake may make it easier for a gymnast to
increase body fat than would increasing carbo-
hydrate intake. This relationship between
dietary fat intake and body-fat percentage is well
elaborated. In a review of five studies that evalu-
ated this relationship in both males and females,
all have shown a positive relationship between
fat intake and body fat storage (Dattilo 1992).
Assuming that the gymnastics surveys represent
a true reflection of the energy distribution of
gymnasts, it appears that most gymnasts would
benefit by lowering fat intake and increasing the
intake of carbohydrates. However, since carbo-
hydrates provide energy in a lower density
package than fats, it is conceivable that gymnasts
could consume a greater volume of food and still
obtain less total energy. Therefore, care must be
taken that this shift in the intake of energy sub-
strates does not further reduce the already inade-
quate energy intake of gymnasts.
To further discourage gymnasts from consum-
ing a low-carbohydrate diet, there is evidence
that low-carbohydrate diets, consumed in con-
junction with exercise and training, adversely
affect the mood state of the athlete (Keith et al.
1991). While there are limited data on male gym-
nasts, two surveys indicated that protein intake
in male gymnasts is 2.0 g · kg–1· day–1, or more
than 20% of total energy from protein (Short &
Short 1983; Brotherhood 1984). By most
measures, this level of protein intake is excessive
and is not likely to be optimal for gymnasts
(Tarnopolsky et al. 1988; Kaufman 1990; Butter-
fieldet al. 1992). (For information on protein
requirements in athletes, see Chapter 10.)


The issue of creatine intake (either as pre-
formed creatine from dietary meat, or as a crea-
tine monohydrate supplement) is an important
one to consider, since several studies have
reported that athletes involved in high-intensity
anaerobic sports may benefit from a higher level
of creatine intake (Harris et al. 1992; Greenhaff et
al.1993; Balsom et al. 1995; Maughan 1995). In a
recently completed study on elite female gym-
nasts, it was found that those consuming creatine
monohydrate during an intensive 3-day training
camp were better able to maintain anaerobic
power and anaerobic endurance than those con-
suming an energy-equivalent placebo (Kozak
et al. 1996). Since these gymnasts consumed less
than their predicted requirement for energy, it is
not possible to know if the same result would
have been seen with adequate energy consump-
tion. (Creatine metabolism, phosphocreatine and
creatine monohydrate supplementation are sub-
jects covered in Chapter 27.)
Given the substantial scientific evidence that
diets high in carbohydrates, moderate in protein,
and low in fat provide the best mix of fuels for
both aerobic and anaerobic activities, there is
little reason to support another type of a dietary
regimen. A starting point for gymnasts would be
to increase complex carbohydrate intake and
decrease fat intake, all with an eye toward sup-
plying sufficient nutrient and energy to meet
physiological needs.

Nutrient intake

What follows is a review of surveys that have
evaluated nutrient intake in gymnasts. In
general, these surveys indicate that gymnasts
typically have intakes that are below established
recommended levels in one or more nutrients,
likely because total energy intake is also below
desired levels. It is difficult to predict the true
requirement for nutrients in this population
because, although growing, they are small in
stature with a higher proportion of metabolic
mass than the average for people their age.
Most nutrient requirements for highly active
anaerobic (power) athletes have not been well

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