Nutrition
for training and racing – Alpine Skiing
Introduction
The average UK diet consists of about 40% of
calories from carbohydrate, 40% from fat and 20% from protein. This average
diet is not ideal for anyone because of the health implications, but is especially
unsuitable for a young athlete who is training hard.
Dietary intake of carbohydrate, fat and protein
needs to be modified for athletes who are training on a regular basis, and
should be further modified in the days preceding a competition. These notes
attempt to cover the important points that should be considered when thinking
about your diet during training and racing.
TRAINING DIET
The training diet should aim to:
1) help you recover quickly from your previous
training session.
2) help you maintain an optimal weight.
3) give you a balanced intake of nutritious foods and essential nutrients.
4) taste good, because if you don’t enjoy your food you will change it.
The key to achieving all these goals is to eat
a wide variety of foods. You don’t have to stop eating all foods that are
high in protein and fat to have a good high carbohydrate diet, you just have
to cut down on those types of foods and emphasise the foods that are high
in carbohydrate.
Why do we want a high carbohydrate diet?
Carbohydrate is the predominant fuel source
when skiing, and performance will be reduced if you run out of carbohydrate.
Many scientific studies have shown that dietary manipulation and carbohydrate
feeding during exercise can improve performance. Fat is not a major fuel source
during ski racing, it is used during more prolonged lower intensity work.
Protein is used only minimally as a fuel in very prolonged exercise, where
carbohydrate stores are depleted, and so is mainly important in a skier’s
diet for tissue growth and repair.
The muscle stores of carbohydrate (glycogen)
can only sustain about 2 hours of activity when eating a moderate carbohydrate
diet. The normal UK diet will not allow you to undertake this much exercise
without additional food intake. Daily training will result in a gradual lowering
of the muscle carbohydrate stores if the dietary carbohydrate intake is less
than about 50% of total calorie intake.
What foods are high in carbohydrate?
There are two main types of carbohydrate –
sugars and complex carbohydrates. Complex carbohydrate sources include cereals,
bread, rice, pasta, potatoes, fruit, lentils and vegetables. Although some
vegetables (lettuce, tomato, cucumber, beans) are good sources of essential
vitamins, minerals and fibre, they are not high in carbohydrate, so these
should be served along with a good source of carbohydrate. Sugar products
like boiled sweets, honey and table sugar are good sources of carbohydrate,
but provide no other nutrients. Sugary foods are good for refuelling during
and after training to help restore muscle carbohydrate stores when lots of
bulky complex carbohydrate cannot be eaten easily.
Why do we need to reduce fat intake, and
what is high in fat?
Most UK diets contain about 40% of energy from
fat. Not only does a high fat intake have health implications, but it also
reduces the amount of energy intake from carbohydrate by slowing emptying
of the stomach and absorption into the blood stream. Choose low fat products
if possible (skimmed or semi-skimmed milk, reduced fat cheese) and remove
all excess fat from meats and poultry prior to cooking. Cook using minimal
oil, and try to grill instead of frying food. No chips/crisps/chocolate. Any
meal with cheese or cream sauces like lasagne may be high in fat if reduced
fat milk or cheese was not used in preparation. Beware of products indicating
that they are ‘low-cholesterol’ or ‘light’ – neither of these mean that they
are necessarily low in fat. Try to read the nutritional information on products
and determine which are low in fat.
What is the fluid requirement for athletes
in training?
The human body requires about 2 litres of fluid
per day for normal functioning, even in an inactive person. An active person
will require more than this depending on the climate, but the key point is
that performance of an athlete will decline with a relatively small amount
of dehydration.
-
During exercise performed at 10-15degC you
can lose as much as 1 litre of sweat per hour. If no fluid is taken in,
this will result in a 1kg reduction in body weight from fluid loss alone.
-
When the temperature is high or thermal
stress is elevated by warm clothing, this fluid loss can exceed 2-3 litres
per hour.
-
Although skiing is performed in a cold or
cool environment, the insulation of clothing can make the heat strain
quite large.
-
You will lose 0.5 litres per hour at high
altitude, on the glacier.
To replace the fluid loss during exercise, you should aim to consume 1.5 times
your fluid loss with an appropriate drink to restore your fluid level as quickly
as possible.
Suggested drinks:
- Hot drinks (eg fruit tea with honey).
- Water (for low/medium intensity training up to an hour in duration) – best
means of rehydration in young people.
- Isotonic sports drinks (for high intensity work over a longer period) –
may lead to dental problems, so you must have regular check-ups.
- Ribena with honey if you want to add some carbohydrate.
Fluid can also be ingested in the diet by eating pasta or rice, both of which
have high water content when cooked, but fluid must also be taken in. Sports
drinks have the added advantage that they supply carbohydrate following training.
It is important to note that you cannot learn to cope with dehydration. A
large loss of water is potentially life threatening. Running out of carbohydrate,
on the other hand, just reduces your performance and eventually makes you unable
to exercise.
How do I eat all the carbohydrate I need?
Eating a high carbohydrate diet can make your diet very bulky, and it may not
be possible to eat all that you need in three meals a day. Athletes are advised
to eat more frequently during the day, and have snacks between meals. However,
be aware of your energy needs and don’t overeat because you’ll quickly put on
excess weight.
Some examples of appropriate snacks are:
Bananas, jam sandwiches, nuts and raisins, wine gums/jelly babies, and Jaffa
cakes (low fat, high carbohydrate).
Your meals should fit round your training schedule so that you’re not eating
then immediately training. (Uphill transport usually takes care of that particular
problem, particularly in Saas Fee!). You should eat 1-2 hours before training,
have snacks to eat during training, and have a good break during the day to
refuel.
Muscle glycogen is best replaced 20-40minutes after exercise, so take a snack
with you to eat on the way down the hill.
You should aim to eat a high carbohydrate meal within 1-2 hours following
training to maximise the rate of muscle glycogen refuelling. Sometimes you
will find that your appetite may be suppressed, and in these cases you should
drink a high carbohydrate beverage.
The key points are:
- Eat what you need and not just what is available, and eat consistently.
- Stick to a high carbohydrate diet.
- Try to adopt a lower fat strategy.
- Don’t overeat when under stress or bored.
- When you are growing and require extra energy intake, make this predominantly
from a high carbohydrate source.
- You don’t need to take protein or vitamin supplements to gain muscle mass,
increase weight or improve performance – plenty will be available in your
diet already if you eat well.
PRE-RACE DIET
The pre-race diet should aim to:
- Boost your carbohydrate stores.
- Ensure that you are adequately hydrated.
- Ensure full recovery between 1st and 2nd runs.
To achieve these aims you will need to increase your percentage intake of carbohydrate
2-3 days prior to a race, as well as tapering your training sessions to ensure
you are well prepared. Make sure you have plenty of fluids to drink in the days
preceding a race, so that you are well hydrated.
What should I do if competing regularly?
If you have two or more races close together, try to fully hydrate between
races (possibly with an isotonic sports drink), and eat a carbohydrate meal
as soon as possible after each race. Do not eat a big meal less than 4 hours
prior to a race or a light snack less than 1 hour before a race. Make sure you
have a light snack with you in case your race starts later than you expect.
Most importantly, work out what works for you during training, as everyone will
be different in their approach to eating before competition.
How do I avoid dehydration?
Keep drinks with you at all times before a race. Remember that thirst isn’t
a good indicator of dehydration, so drink small amounts frequently during the
day if possible. Keep drinks cool – they taste better that way! Make sure you
have enough fluid with you.
How can I have a high carbohydrate diet when travelling
to a competition?
Canteen food may be tempting, but will generally be higher in fat than you
want. If possible take food with you, but otherwise choose wisely! (eg pizza
with thick base, not too much cheese; pasta - but no creamy or cheese sauce).
SPECIAL DIETARY NEEDS
Females and nutrition
Female athletes tend to have more problems with nutrition, and tend to be more
weight conscious than males. Poor nutrition which often occurs in an attempt
to lose weight will affect not only your performance, but may have more general
effects on your hormone balance.
Menstruating female athletes may find that their diet does not provide enough
calcium or iron.
Calcium is essential for healthy teeth and bones, and is obtained mainly
from dairy products. Low-fat dairy products are usually calcium-enriched, so
calcium intake may be boosted without increasingly dietary fat intake.
Iron is an essential component of the haemoglobin in the red blood cells
that carry oxygen around the body. Any loss of iron (through menstruation or
low iron intakes) may result in reduced oxygen carrying capacity, and will lead
to poor performance. Iron intake can be increased by eating red meats (ferrous
iron) and vegetable (ferric iron). Ferrous iron is absorbed more readily than
ferric iron, which puts vegetarian athletes at greater risk of suffering from
iron-deficiency anaemia. It is understandable then that vegetarian female athletes
are most susceptible to iron deficiency. The inclusion of vitamin C rich products
(fresh orange juice) in a meal can increase iron absorption and is useful for
vegetarians to increase iron stores.
Should I take dietary supplements to increase
vitamin and mineral intake?
There is no evidence for a beneficial effect
of taking vitamin or mineral supplements if you have a well-balanced diet.
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Date last modified 14-Nov-2008