Nutrition in Combat Sports

1 Nutrition in Combat Sports 13
the athlete from undertaking their recommended dietary practices and by promoting
high-risk behavior [32] .
1.7 Meeting Needs for All Nutrients
All athletes want to be able to train hard and compete without the interruptions of
illness and injury. Maintaining optimal health and performance requires the intake of
a large number of nutrients and food chemicals. In general, when athletes consume
an adequate energy intake and a wide variety of nutrient-dense foods, they are likely
to meet their requirements for all these compounds. However, not all combat athletes
consume adequate energy or a varied diet. Challenges include energy restriction for
weight loss in general, fad weight loss diets, fussy eating, poor nutrition knowledge
and awareness, and limited access to a variety of foods while traveling. The expertise
of a sports dietitian/nutritionist may be valuable in assessing inadequate intakes of
nutrients and educating the athlete to improve the quality and quantity of their food
intake. At times, a vitamin–mineral supplement may be needed when it is not possible
to achieve these changes – for example, during prolonged travel or a lengthy period
of restricted energy intake to achieve weight loss and body composition goals.
The most common micronutrient deficiency among athletes, just as it is in the
general population, is iron deficiency. Regular strenuous exercise causes the alteration
of various measures of iron status, due to changes in plasma volume or the
acute phase response to stress. Therefore, conventional hematological standards are
often inappropriate for diagnosing the true prevalence of problematic iron deficiency
in athletic groups. Inadequate iron status can reduce exercise performance
via suboptimal levels of hemoglobin, and perhaps also via changes in the muscle
including reduced myoglobin and iron-related enzymes (for review, see [33]).
However, it is often difficult to detect the stage of iron deficiency at which impairments
to exercise performance are observed. Despite initial conflict in the literature,
it now appears that iron depletion in the absence of anemia – i.e. reduced
serum ferritin concentrations – may impair exercise performance [33] . In addition,
athletes with reduced iron stores complain of feeling fatigued and failing to recover
between a series of competition or training sessions. Combat sport athletes who
restrict energy intake over long periods to meet weight goals should be considered
at high risk for an inadequate intake of iron. It makes sense to monitor these athletes
for iron depletion and to intervene as soon as iron status appears to decline substantially
or to symptomatic levels.
The evaluation and management of iron status in athletes should be undertaken by
a sports physician. It is tempting for fatigued athletes to self-diagnose iron deficiency
and to self-medicate with iron supplements which are available over-the-counter.
However, there are dangers in self-prescription or long-term supplementation in the
absence of medical follow-up. Iron supplementation is not a replacement for medical
and dietary assessments and therapies, since it typically fails to correct the underlying
problems, which have caused iron drain – factors causing iron requirements and