The clear message from over a half a century of
scientific research on the links between food, nutrition and exercise
capacity is that next to natural talent and appropriate training,
carbohydrate ingestion for energy and adequate fluid intake to avoid
dehydration are the two most important elements in the formula for
successful participation in sport.
When
carbohydrates are ingested, they are broken down into glucose and
stored in the muscles and liver as glycogen. Glucose circulates in the
blood and this is also known as blood sugar. The brain and nervous
system relies on glucose for energy, with the brain using a massive 70%
of your available blood glucose. If your brain cells are deprived of
glucose, mental power suffers and so does performance.
While protein and fat are primarily building materials, carbohydrates
are unmatched at storing energy for easy and quick use when your body
requires it. Carbohydrate also spares protein from being used as
energy, leaving it to do its main job of building and repairing muscle.
On top of helping to build muscle, carbohydrates also help in burning
fat, providing the energy source for fat oxidation (burning). Without
carbohydrates, fat wouldn't burn as well.
During
exercise, your body relies on both fat stores and carbohydrate for
energy. Fat is burned for fuel at about the same rate, whether it is
low or high intensity. As the intensity increases so to does the body's
reliance on carbohydrate for energy. The dilemma for athletes is that
glucose and glycogen stores are in very limited supply. Low
concentrations of carbohydrates force your muscles to rely more on fat
to provide energy.
When burning fat, performance
decreases significantly, forcing you to stop, and otherwise known as
'hitting the wall', 'bonking', 'seeing Elvis' or 'got nothin'. The take
out message from this is also clear; if you intend exercising for more
than an hour, make sure you are ingesting carbohydrate. Whether it is
energy gels or energy bars, you will be able to perform longer and at a
higher intensity.
Before
energy can be used, it must first be transformed into a form which the
body can handle easily. It is proven that ATP is formed a lot faster
from carbohydrates than fat - in fact carbohydrates provide
approximately twice the amount of energy than fats in the same time.
During anaerobic exercise (high intensity) which uses only
carbohydrates as fuel, the energy formation is almost five times faster
than fats.
Besides consuming a healthy diet and supplementing wisely, specific nutrition strategies around training are also beneficial.
When your immune system is compromised from training, you'll find
elevated concentrations of stress hormones in the body. Specific
nutritional strategies to boost the immune system around training
sessions therefore need to be focused on reducing this stress hormone
response to create less disturbance in blood immune cell counts, and
lower oxidative activity.
Some of the most important nutritional strategies centre around
carbohydrate intake before, during, and after training - a familiar
practice for endurance athletes. Training with optimal stores of
carbohydrate not only provides fuel for your workouts, but supports a
strong immune system. It's known that endurance athletes who train in a
carbohydrate-depleted state experience greater increases in their
stress hormones. Consuming carbohydrate before, during, and after
endurance exercise appears to diminish some of the immunosuppressive
effects of intense training, lowers cortisol levels, leads to less
changes in blood immune cell counts, lowers oxidative activity, and
diminishes inflammatory response.