Nutrition may not create a good athlete, but it could be one of the factors that make a GREAT
athlete. Sports performance is mostly determined by genetic potential, training, and
psychological drive. Nutrition is one of those ‘X’ factors that can put one athlete above
another. Nutrition plays a vital role in fueling the body to be able to train, replacing any
losses that occur as a result of training, allowing for training adaptions to happen, and
ensuring proper hydration. Inadequate nutrition at any of these points will have a negative
effect on athletic performance.
Fuel
Our body needs energy to perform basic physiological functions, but when we exercise, our
need for energy increases drastically. The amount of energy that our body uses depends on
the intensity and duration of the exercise. During exercise, carbohydrates are our body’s
preferred energy source, but we can also get energy from fat. We can store energy in the
muscle and liver, which is the initial source of energy utilized when exercising. Once our
energy stores are depleted, the body relies on energy in the blood, which is maintained by
eating food.
For optimal performance, you want to ensure that you start every exercise session will full
energy stores to delay the time to fatigue. This means that you need to fuel up before
training. You can do this the day before exercise by providing foods rich in carbohydrates
throughout the day and ensure that you have a carbohydrate-based snack or meal before an
exercise session.
For endurance exercise (lasting more than 90 minutes), you will likely deplete energy stores
and need to provide energy through eating to fuel the rest of the exercise session. If you
don’t provide energy, your exercise performance will decline. Once the exercise session is
complete, you then need to replace energy stores. Eating carbohydrate-rich foods immediately
after exercise will help with fast energy replenishment. This is particularly important if
you will be training again in less than eight hours. If your next exercise session is only
in 24 hours, eating regular meals that contain carbohydrates throughout the day will help to
ensure adequate replenishment.
Ensuring that you provide a sufficient amount of fuel before, during, and after exercise is
crucial to allow for adequate energy for training and competition.
Recovery
Training results in the breakdown of old muscle fibers; the body can then rebuild the
muscles via a process called protein synthesis. This allows the body to become stronger and
more efficient at performing the exercise. The rebuilding of damaged tissue relies on
available nutrients. What and when you eat after exercise will affect your body’s recovery
and, therefore, how well your body adapts to your training.
Dietary protein is key to providing the essential amino acids to promote protein synthesis.
We have a 30 minute window period after exercise where protein synthesis is at its optimal.
Providing a good quality protein source will help to stimulate protein synthesis and,
therefore, training adaptions. Carbohydrate intake, together with protein, is also essential
as it will also promote muscle rebuilding and will provide available energy for adaptions to
occur.
After that, providing a continuous supply of protein throughout the day (at main meals and
snacks) will help to ensure adequate nutrients are available for recovery.
Hydration
During exercise, we lose most of our fluid through sweat. We also lose electrolytes,
specifically sodium, potassium, and phosphorus. Fluid requirements are individual and vary
according to the environment and the duration and intensity of the exercise.
Inadequate hydration can have a direct effect on performance. As your hydration declines, so
your perception of fatigue increases, which will make exercising feel harder. If you become
dehydrated, not only will it reduce your performance, but it could also potentially stop you
from finishing your event. Dehydration occurs as a result of increased fluid loss without an
adequate replacement.
Conversely, overhydration can also affect performance. Overhydration increases weigh and can
lead to hyponatremia, which is a life-threatening condition. Overhydration occurs when there
is excess fluid intake and a significant sodium deficit as a result of loss through sweat
and inadequate replacement. This leads to an increase in total body water retention, which
reduces blood sodium levels further.
Managing your hydration before, during, and after exercise is an essential component of
ensuring optimal performance. Starting training or an event in a normally hydrated state
will help prevent dehydration during exercise. Matching your fluid and electrolyte losses
with your intake during exercise will further prevent dehydration and overhydration. After
exercise, it is just as important to ensure that you replace any losses to assist recovery,
provide adequate hydration for the next exercise session, as well as replace additional
losses as you will continue to lose fluid post-exercise.
Conclusion
An important component to ensure optimal performance is making sure that your nutrition is
tailored for your exercise. Having a good performance nutrition strategy can improve sports
performance by ensuring that you are fuelled and hydrated before and during exercise and
that you recover after exercise to support training adaptions and replace what was lost.
Nutrition should always be a main consideration for anyone wanting to perform well in their
sport.
Written by: Michelle Tolmay, Registered Dietitian, Kings Park Sports
Medicine Centre.