more quickly absorbed and has increased effects.
Therefore it is important to examine the effects
of alcohol on processes that are important in
the recovery from prolonged exercise, and on
the performance of subsequent exercise bouts.
Unfortunately, postexercise drinking is subject to
many rationalizations and justifications by ath-
letes, including ‘everyone is doing it’, ‘I only
drink once a week’ and ‘I can run/sauna it off the
next morning’.
Rehydration
The restoration of the body fluid deficit incurred
during exercise is a balance between the amount
of fluid that athletes can be induced to drink
after exercise, and their ongoing fluid losses. The
palatability of postexercise fluids is an important
factor in determining total fluid intake, while
replacement of sodium losses is a major determi-
nant of the success in retaining this fluid (see
Chapter 19). It has been suggested that beer is
a valuable postexercise beverage since large
volumes can be voluntarily consumed by some
athletes! However, the absence of an appreciable
sodium content (unless it is accompanied by the
intake of salty foods), and the diuretic action
of alcohol are factors that are likely to pro-
mote increased urine losses. A recent study
(Shirreffs & Maughan 1997) examined the effect
of alcohol on postexercise rehydration from an
exercise task which dehydrated subjects by 2% of
body mass. Subjects replaced 150% of the volume
of their fluid deficits with drinks containing 0%,
1%, 2% or 4% alcohol within 90 min of finishing
the exercise. The total volume of urine produced
during the 6 h of recovery was positively related
to the alcohol content of the fluid. However, only
in the 4% alcohol drink trial did the difference in
total urine approach significance, with a net
retention of 40% of ingested fluid compared with
59% in the no-alcohol trial, equating to a differ-
ence of about 500 ml in urine losses. Subjects
were still dehydrated at the end of the recovery
period with the 4% alcohol drink, despite having
consumed 1.5 times the volume of their fluid
deficit (Fig. 30.1). Although individual variabil-
ity must be taken into account, this study sug-
gests that the intake of significant amounts of
alcohol will impede rehydration. It also indi-
cated that beer is not a suitable rehydration
drink, even in the low alcohol forms that are
available, because of the low content of elec-
trolytes, particularly sodium (Maughan &
Shirreffs 1997).
In practical terms, low alcohol beers (<2%
alcohol) or beer ‘shandies’ (beer mixed in equal
proportions with lemonade, thus diluting the
alcohol content and providing some carbohy-
drate) may not be detrimental to rehydration.alcohol in sport 409
10005000–500–1000–1500–2000
Pre-
exercisePost-
exercise01 23456Time after rehydration (h)Net fluid balance (ml)Fig. 30.1Whole-body water
balance after exercise- induced
dehydration followed by
ingestion of a volume equal to 1.5
times the sweat loss of fluids
containing alcohol at
concentrations of 0% (), 1% (),
2% () and 4% (). There is
clearly an increasing urine output
in the postingestion period as the
alcohol concentration increases.
Adapted from Shirreffs and
Maughan (1997).