of the function and performance that was lost
during an acute episode of a rapid or a moderate
rate of weight loss can be regained within 5–20 h
providing ample food and beverage are available
and the athlete is willing to eat. There are still
many questions to be answered regarding the
total efficacy of eating and drinking during this
period between weigh-in and competition with
respect to regaining normal physiological func-
tion and performance. The issue of replacing car-
bohydrate postexercise is covered in Chapter 7,
and rehydration after exercise-induced sweat
loss is covered in Chapter 19.
Practical considerations for
weight loss
As stated in a previous section of this paper, the
ideal way to lose weight for competition is to
establish a goal weight several months in
advance of the start of the competitive season,
and achieve this goal weight by gradual reduc-
tions in body fat of not more than 0.45–0.9 kg ·
week–1while maintaining or increasing the fat-
free mass. Koutedakis et al. (1994) have shown
that weight reduction of the same magnitude
(6–7% of body weight) over 2 months vs. 4weight category sports 643
Table 49.3Alterations in physiological function and performance consequent to rapid and moderate rates of
dehydration. Data from reviews of Fogelholm (1994), Horswill (1994), Keller et al. (1994) and Oppliger et al.(1996).
Variables Dehydration RehydrationPhysiological function
Cardiovascular
Blood volume/plasma volume ØØ*
Cardiac output Ø?
Stroke volume Ø?
Heart rate ≠?
Metabolic
Aerobic capacity (V.
o2max.) ́,Ø ́*
Anaerobic power (Wingate test) ́,Ø ́,Ø
Anaerobic capacity (Wingate test) ́,Ø ́,Ø
Blood lactate (peak value) ØØ*
Buffer capacity of the blood Ø?
Lactate threshold (velocity) Ø?
Muscle and liver glycogen ØØ
Blood glucose during exercise Possible Ø?
Protein degradation with exercise Possible ≠?
Thermoregulation and fluid balance
Electrolytes (muscle and blood) Ø ́
Exercise core temperature ≠?
Sweat rate Ø, delayed onset?
Skin blood flow Ø?
Performance
Muscular strength ́,Ø ́,Ø
Muscular endurance ́,Ø ́,Ø
Muscular power? ؆
Speed of movement??
Run time to exhaustion Ø?
Total work performed ØØ*
Wrestling simulation tests† Ø ́؆Ø, decrease; ≠, increase; ́, no known change, or return to normal values; ?, unknown.
- From Burge et al.(1993).
† From Oopik et al.(1996).