NUTRITION IN SPORT

(4800 kcal). Therefore, for some of the players the
total energy consumption was much lower than
required.
The quality of the diet must also be considered,
e.g. the proportion of protein, fat and carbohy-
drate. The players’ diet contained, on average,
14% protein of total energy intake (which lies
within the recommended range), 47% carbohy-
drate and 39% fat. If these percentages are com-
pared with those recommended of at least 60%
carbohydrate and no more than 25% fat, it is
evident that the carbohydrate intake by the
players was too low on the days before the Euro-
pean Cup match. This factor, together with the
relatively low total energy consumption of some
players after the Sunday match, can explain the
low muscle glycogen stores found on the days
prior to the European Cup match. Thus, the diet
of the players was inadequate for optimal physi-
cal performance.
It is evident that many athletes in team sports

580 sport-specific nutrition

are not aware of the importance of consuming

large amounts of carbohydrates in the diet. It

may be possible to achieve major changes in

dietary habits just by giving the players appro-

priate information and advice.

In the study concerning the effect of a

carbohydrate-rich diet on intermittent exercise

performance, 60% of the soccer players’ diet was

controlled and within given guidelines they

could select the remaining 40% themselves.

Using this procedure, the average carbohydrate

intake was increased from about 45% in the

normal diet to 65% in the high-carbohydrate

diet. The foods that were consumed in the

carbohydrate-rich diet are found in most house-

holds. This means it is not necessary to drasti-

cally change dietary habits in order to obtain a

more appropriate diet.

Everyday diet

carbohydrates

It is clear that eating a carbohydrate-rich diet on

the days before a match is of importance for per-

formance. To consume a significant amount of

carbohydrate in the everyday diet is also benefi-

cial to meet the demands of training. Figure 44.7

illustrates how the muscle glycogen stores may

vary during a week of training for a player that

consumed either a high-carbohydrate diet or a

‘normal’ diet. During training, some of the glyco-

gen is used, and between training sessions the

stores are slowly replenished. If the diet contains

large amounts of carbohydrate, it is possible to

restore glycogen throughout the week. This

may not be achieved if the diet is low in

carbohydrates.

An increase in glycogen storage is followed by

an enhanced binding of water (2.7 g water · g–1

glycogen). Thus, a high-carbohydrate diet is

likely to result in an increase in body weight,

which might adversely affect performance in the

early stage of the match. However, this effect is

probably small and the benefit of high muscle-

glycogen concentrations before a match will

probably outweigh the disadvantages of any

100

75

25

Glycogen content (%)

50

Pre-matchPost-match24 hpost-match48 hpost-matchPre EuropeanCup match

Fig. 44.6The muscle glycogen content of a quadriceps
muscle for players in a Swedish top-class soccer team,
before and just after a league match (Sunday). The
figure also gives muscle glycogen values 24 and 48 h
after the match, and an estimate of the level before a
European Cup match on the following Wednesday
(dashed bar). The values are expressed in relation to
the level before the league match (100%). Note that
muscle glycogen was only restored to about 50% of the
‘normal level’ before the European Cup match.
Adapted from Bangsbo (1994b), with permission from
HO+Storm.