a. About 55–70% (6–10 g/kg body weight or 8–10
kcal/kg body weight) of the diet should be in the
form of carbohydrates.
b.About 25–30% of the diet should be from fats.
c. About 12–15% (1–1.5 g/kg body weight) of the
diet should be high quality protein (American
College of Sports Medicine, 2000).
•Athletes are always looking for something that will
give them an advantage over their competitors. There
are many ergogenic aids that are available, both
legally and illegally, to athletes in an attempt to
improve their performance. Carbohydrate loading has
been proven to improve performance during
endurance events. Caffeine ingestion of 3–5 g/kg also
improves endurance performance for many athletes.
This dose typically has an ergogenic effect without
exceeding those serum levels banned by sport govern-
ing bodies (Paluska, 2002).
- Carbohydrate loading has been a proven method to
increase endurance event performance since the
late 1960s. This technique has been shown to
increase the glycogen stores in the muscles being
exercised in events that last longer than 90 min. - The older method of depleting glycogen stores, 1
week of exhaustive exercise in conjunction with 3
days of a low carbohydrate (less than 100 g/day)
diet prior to 3 days of carbohydrate loading with
minimal exercise, is no longer recommended due
to significant undesired side effects (irritability,
hypoglycemia, stiffness and heaviness of muscles,
diarrhea, dehydration, and chest pain in older ath-
letes) (DiMarco and Samuels, 2001). - The current recommendations for carbohydrate
loading are a diet composed of 60–70% carbohy-
drates and a decrease in the training regiment
during the 3 days prior to competition.
- Athletes need to experiment with an individualized
preevent and intraevent fuel source that will help to
minimize the risk of glycogen depletion, dehydration
and poor performance. Triathletes should never utilize
a new hydration–nutrition regimen on race day.
- High fat and protein containing foods should be
avoided in the 3 h prior to competition. About
150–300 g of carbohydrate in any form is recom-
mended. Some competitors recommended 1g/kg of
body weight of carbohydrate 1 h before competi-
tion. There is no evidence that this will improve
performance and is more of an anecdotal recom-
mendation that athletes need to decide for them-
selves about. - About 30–60 g/h of carbohydrate during events that
last longer than 1 h has been proven to be beneficial
to performance. Glucose and sucrose should be the
primary carbohydrates ingested as they provide
more energy and have fewer side effects than fruc-
tose. Newer studies suggest that a small amount of
protein along with carbohydrates may have an even
better effect on endurance performance (Convertino
et al, 1996).
3.Following postevent rehydration, ingestion of
foods high in carbohydrates along with a moderate
amount of protein should be consumed to help
with the repair and maintenance of muscle tissue.- Hydration
- Hydration is the most important factor affecting
performance. As little as 2–4% dehydration has
been shown to negatively affect performance.
2.Water loss occurs primarily through sweat.
Ambient temperature, humidity, exercise intensity,
and rate of fluid intake all play a role in the overall
hydration status of a competitor. Competitors can
lose 2 to 6% of their body weight during a race as
a result of sweating. Trained athletes can lose
1–3 L of sweat per hour.
a. Average competitors do not consume enough
fluid to negate the fluid lost. Consuming bever-
ages while biking is a little easier and more pro-
ductive than drinking while running. Elite
runners may consume as little as 200 mL of
fluid during distance events that last over 2 h.
b.Minimal dehydration leads to impaired heat dis-
sipation due to decreased skin blood flow,
decreased plasma volume and can lead to severe
hydration that can lead to decreased stroke
volume, increased heart rate, and possibly heat
stroke. - Starting an event hydrated or slightly overhydrated
will be beneficial to the competitor, as we know
that by the end they will be dehydrated.
Competitors need to force hydrate themselves the
day prior to the competition and consume 400 to
600 mL up to 2 h prior (Convertino et al, 1996). - Ideally an athlete will replace fluids at a rate that
equals their loss. A loss of 500 mL of fluid equates
to a 1-lb decrease in body weight. This can be an
excellent guide to post competition fluid replace-
ment needs (Fieseler, 2001). - The frequency and amount of fluid consumed by
an endurance athlete is a topic of great interest
with recommendations changing as more research
on the topic is published. About 150 to 300 mL of
water every 15 to 20 min of exercise depending on
sweat rate is recommended.
a. Too little or too much hydration each lead to
their own set of problems—dehydration and
hyponatremia respectively, so consuming the
proper amount is paramount to maximizing per-
formance.
- Hydration is the most important factor affecting
542 SECTION 6 • SPORTS-SPECIFIC CONSIDERATIONS