NUTRITION IN SPORT

(Martin Jones) #1

effort itself, but there must be, during the post-
exercise period, an altered gene expression to
cause an enhanced synthesis of specific proteins.
To achieve these aims during the training
period, athletes normally follow a training pro-
gramme containing microcycles lasting 3–5 days.
Each training microcycle is constructed to allow
adaptation of all of the different functions which
respond to the specific training undertaken.
Complete adaptation in response to this type of
training usually appears after three to five repeti-
tions of the cycle (Lamb 1984).
The diet consumed by the athlete during this
training phase should be designed to supply the
necessary energy and nutrients in order to maxi-
mize the efficiency of the training process. Prepa-
ration of the diet requires a knowledge of the
total energy demand, but also some understand-
ing of the specific character of the training pro-
gramme at any given time. Energy expenditure
of strength and power athletes during periods of
heavy training is typically about 14.6–18.8 MJ
(3500–4500 kcal), depending on body weight,
and the preparation of a balanced diet is not diffi-
cult to achieve. However, it appears that at some
times in the training cycle of these athletes, there
is a need for an increase in the dietary protein
intake if muscular development is to occur. To
meet the protein requirement of weightlifters,
sprinters and throwers, for example, it is recom-
mended that the daily protein intake should be
1.4–2.0 g · kg–1body mass (Rogozkin 1993). This is
slightly higher than the intake of 1.4–1.7 g · kg–1
recommended by Lemon (1991). It is not only the
total protein intake that is important, but also the
content and balance of the essential amino acids,
and the proteins in meat, fish and dairy produce
have a higher biological value than those in other
foods. Dairy products have a high content of the
sulphur-containing amino acid methionine,
which is indispensable for the synthesis of
muscle protein (Williams 1976).
The fat intake for athletes from these sports
should be approximately 2 g · kg–1· day–1, and a
significant part of this will be provided by the
protein-rich foods in the diet, especially meat


and dairy produce. Vegetable oils, however,
including sunflower seed, corn and nut oils, are
valuable sources of the essential polyunsatu-
rated fats, which may comprise as much as
50–60% of their total fat content. Dietary fat is
also important in ensuring an adequate supply
and uptake of the fat-soluble vitamins A, D and
E. A carbohydrate intake of 8–10 g · kg–1· day–1
should be sufficient to meet the needs of the
organism even during the heaviest training.
The requirements of the strength athlete for
vitamins and minerals have been identified, and
the recommended intakes are shown in Table
47.2 (Rogozkin 1993).
The following general and specific recommen-
dations are made.
1 The energy requirement for the athlete in train-
ing should be completely satisfied from non-
protein sources (carbohydrate and fat).
2 The diet should contain an increased amount
(15–20%) of energy from protein, consisting of
biologically valuable and easily assimilated pro-
teins from various sources, including meat, fish,
milk and eggs.
3 Meals with a high protein content should be
eaten no less than five times per day.
4 There must be optimal conditions for the
assimilation of the protein components of foods.
After training, meat should be taken together
with vegetables, and during the intervals

weightlifting and power events 627


Table 47.2Recommended daily intakes of vitamins
and minerals for athletes during periods of intensive
strength training.

Vitamins Minerals

C 175–200 mg Phosphorus 2.5–3.0 g
B 1 2.5–4.0 mg Calcium 2.0–2.4 g
B 2 4.0–5.5 mg Potassium 5.0 –6.0 g
B 3 20 mg Magnesium 0.5–0.7 g
B 6 7–10 mg Iron 25–35 mg
B 9 0.5–0.6 mg Zinc 25–35 mg
B 12 4–9mg Iodine 150–200 mg
PP 25–45 mg Chromium 10–15 mg
A 2.8–3.8 mg
E 20–30 mg
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