NUTRITION IN SPORT

1988; Bar-Or et al. 1992) suggest that most of the
benefit was obtained through the addition of
NaCl. A limitation to these findings is that the
population was pre- and early pubertal only;
further research is necessary in older children
and adolescents.

Micronutrients

In recent times there has been much concern
over the adequacy of specific micronutrients in
the diets of young athletes. Vitamins, iron
and calcium are most commonly considered,

although zinc, sodium, potassium and magne-

sium have also received attention (Shephard

1982). Supplementation of the diet with vitamins

or minerals is not generally warranted in ath-

letes, irrespective of age: additional demand for

these nutrients imposed by training should be

met if the energy intake is sufficient to meet the

additional energy expenditure incurred in train-

ing and competition, and if a varied diet is con-

sumed. One of the major sources of inadequate

(defined as less than the required RDA) micronu-

trient intake is the actual methodology used to

collect the information. Dietary recall procedures

the young athlete 437

1.0

0.5

0

–0.5

–1.0

0 20 45 65 90 110 135 155 180

Time (min)

Body weight (%)

**†**†

Fig. 32.4Net body weight
changes throughout chamber
sessions in unflavoured water
(W), flavoured water (FW) and
carbohydrate–electrolyte (CNa)
trials. Vertical lines denote SE
values; tinted areas show exercise
periods., swimming; , tennis;
, gymnastics; n=12; *, P<0.05
(CNa–W); †, P<0.05 (CNa–FW).
From Wilk and Bar-Or (1996), with
permission.

0 20 45 65 90 110 135 155 180

Time (min)

*

*†

*

*

*

1500

1200

900

600

300

0

Drink intake (g)

Fig. 32.5Cumulative drink intake
throughout chamber sessions in
unflavoured water (W; ),
flavoured water (FW; ), and
carbohydrate–electrolyte (CNa;
) trials. Vertical lines denote SE
values; tinted areas show exercise
periods.n=12 subjects. *, P<0.05
(CNa–W); †, P<0.05 (CNa–FW).
From Wilk and Bar-Or (1996), with
permission.