between training sessions, special protein sup-
plements should be taken.
5 It is necessary to ensure an adequate intake of
vitamins (B 1 , B 2 , B 6 , C and PP) which promote
protein synthesis and the accumulation of
muscle mass.
Careful attention to diet is necessary during
periods of intensive weight training in order to
create the appropriate metabolic environment to
allow increases in muscle mass to occur.
Diet and weight control
Restriction of energy intake sufficient to result in
a negative energy balance is an essential part
of any successful weight-control programme
(Williams 1976). Most fad diets that promise
rapid loss of body weight stress weight loss
rather than fat loss, and may seriously affect the
athlete’s performance because loss of lean tissue
is likely to account for much of the loss in weight.
These diets are often unpalatable and unhealthy,
and do not represent an eating pattern that
would be possible to sustain on a long-term
basis. A rebound gain of the lost weight is almost
inevitable. The goal of the dietary programme
when weight loss is required should be a loss of
body fat followed by maintenance of that loss.
Many popular diets promote a low carbohy-
drate intake, and these diets may be successful in
causing large weight losses, perhaps as much as
5–10 kg in a few weeks. However, a diet that is
low in carbohydrate will result in depletion of
the liver and muscle glycogen stores and in a loss
of water from tissues. Although the weight loss
seems impressive, there may be little loss of body
fat. Additionally, glycogen depletion greatly
diminishes exercise capacity, leading to a
decreased exercise level, which in turn means a
decreased level of energy expenditure. Periods
of low exercise levels in combination with
restricted energy intake result in a loss of muscle
tissue.
A successful weight-loss programme requires
a negative energy balance. Given that the energy
content of 0.45 kg of fat is about 14.7 MJ (3500
kcal), which is as much as most athletes expend
628 sport-specific nutrition
in day, it is clearly impossible to lose more than a
few pounds of fat in a week. Empirical evidence
suggests that, if weight is lost at a faster rate, the
loss must come increasingly from loss of muscle
mass. Diets that promise large decreases in fat in
a short time are misleading: they are potentially
dangerous and will impair performance.Weight loss and making weight
The aim of all weight-loss programmes should
be to restrict food intake so that the body’s fat
reserve is gradually reduced while the normal
functions of the body are maintained. The only
successful approach is to reduce energy intake
while ensuring that the nutrient density, and in
particular the carbohydrate content, is kept high.
The reducing diet will therefore be achieved by
restricting fat, rather than carbohydrate, intake.
Foods should be chosen to provide not only car-
bohydrate, which should be present mostly in
the form of complex carbohydrates, but also vita-
mins, minerals and trace elements in adequate
amounts, rather than simply being high in fibre.
All visible fat should be removed from meat, and
low-fat foods should be substituted for high-fat
alternatives where these are available. If the diet
is already very low in fat, the only available
option is to reduce the overall amount of food
being eaten.
Making weight is a different situation from a
gradual weight-loss programme. This situation
arises when athletes have to prepare to compete
in a particular weight category. Most athletes
participating in sports with specific weight cate-
gories, including boxing, judo, wrestling and
weightlifting, compete in a class that is 5–10%
below their usual weight. Typical weight reduc-
tion techniques used to induce large weight
losses in a short time include dietary restriction,
fluid restriction, dehydration through exercise in
the heat or in a rubber suit, or sitting or exercising
in a sauna or steam room. Less commonly used
techniques include the use of diuretics and laxa-
tives, vomiting and spitting.
Athletes will commonly lose weight rapidly in
the last few days before competition (3–4 kg in