Nutrition in Combat Sports

2 Making Weight in Combat Sports 29
activity in a dehydrated state such as training to further reduce body weight, the compromised
state of the athlete impairs cardiovascular function [23– 28] and thermoregulation
[24, 29, 30] .
2.5.2 Performance
The debate continues over whether weight reduction to a lower-than-normal body
weight affords a performance advantage to the combat athlete. This review will
examine what research shows in the lab and in the few field studies that exist. Only
those studies that focus on combat athletes will be reviewed. It has been noted that
non-athletes and non-combat athletes used in research to examine the effects of
“making weight” on physical performance may not be relevant to that which occurs
in athletes who have subjected themselves to weight reduction and are accustomed
to performing in a nutritionally deprived state. Because of the limited amount of
research on weight loss in all combat sports, this section will not categorize the
research according to sport.
Physical performance in lab-based research . Previous reviews have addressed
the topic in detail; the readers are referred to them for more details [31– 34] . With
a few exceptions, most of the research on the effect of rapid weight loss on physical
performance in weight-class athletes shows that short-duration high-intensity
performance is less likely to be affected adversely [31, 35, 36] . If the effort is
extended and repeated, i.e., requires an element of endurance, performance deteriorates
[32] . For submaximal efforts of longer duration, performance is clearly
impacted in a negative way [32] . Because most combat sports are relatively short
in duration and a period of time, while short, allows for partial recovery after the
weigh-in, most combat athletes will take advantage of the system and reduce
body mass to make a lighter-than-normal weight class. Considering, though, that
training sessions require longer efforts frequently in warm combat rooms to
facilitate sweating-induced weight loss, the athletes may not be able to optimize
physical conditioning, develop new techniques and strategies that require cognition,
and minimize the risk of heat illness. Prior studies on wrestlers, boxers, and
judoists showed deterioration of mood (although the change may be gender-specific)
[22, 37, 38] , ratings of perceived exertion for a given effort [36] , and cognitive
function [39] concomitant with weight reduction.
There are suggestions in the literature that exercise-induced weight reduction may
be less detrimental than diuretic-induced weight loss for impact on physiology [40,
41] , that diet composition during weight reduction may influence subsequent physical
performance such that hypocaloric but high-carbohydrate diets may be beneficial [22,
42, 43] , and that rehydration by oral means may be preferable to intravenous administration
of an equal volume of fluids for recovery of physiological functions, physical
performance, and perceived exertion of the subsequent effort [30, 44, 45] .
Performance in sport-specific tasks. Because combat sports have a large technical
component associated with the competitive performance, lab-based tests that measure
power, total work, or endurance are arguably lacking. A few studies have attempted