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Sport & Nutrition

What are the benefits of sport for adolescent?

  • Improve strength and endurance
  • Helps build healthy bones and muscles
  • Helps control body weight
  • Reduce anxiety and stress
  • Increases self esteem
  • May improve blood pressure and cholesterol level

Can Body Mass Index (BMI) be used to assess nutritional status of adolescent athletes?

  • BMI is a good method to assess your nutritional status. For optimal performance, your BMI should be between the 10th and 85th percentile. Refer to the table below to know your appropriate BMI for your age.

 

Age (years)
Suitable BMI for boys (kg/m2)
Suitable BMI for girls
(kg/m2)
10
15-19
14-20
11
15-21
15-21
12
16-21
15-22
13
16-22
16-23
14
17-23
17-25
15
17-24
17-24
16
18-24
18-26
17
18-25
18-25
18
19-26
18-24

 

Note :
You can calculate your BMI using this formula :

Weight (kg)
BMI =
Height (m)  X  Height (m)

Example : If you are a 17-year old girl, weighing 60 kg and is 1.7 m high, your BMI is 20. So you have a normal BMI (between 18 – 25kg/m2).

  • However, being athletic your BMI may be higher than normal. This is usually due to muscle build up and the bigger body frame of athletes resulting from high level of physical activity. In this case, other methods such as triceps skin fold thickness will be used to differentiate excess body fat from lean body mass.

What should good diets for adolescent athletes consist of?

Athletic adolescents should eat :

  • Adequate energy to support normal growth and development, and physical activity.
  • Adequate carbohydrate to store energy.
  • Adequate protein intake for growth, but not excessive intake that may increase the risk of dehydration.
  • Adequate fluid intake to prevent dehydration and promote optimal endurance.
  • Adequate, but not excessive fat intake.
  • Variety of fruits and vegetables to provide adequate vitamins and minerals needed for growth and performance (eg. iron and B vitamins).
  • Variety of calcium and vitamin D sources for healthy bones.
  • Iron rich food to prevent anemia, which can lead to low stamina and poor performance.
  • Eat a variety of food according to your calorie needs.

Here is an example of a daily menu for an adolescent athlete who needs about 2500 kcal :

Meal Time
Example
Breakfast
2 slices bread with margarine
1 egg
½ cup breakfast cereals
1 slice papaya
1 glass low fat milk
Mid Morning Tea
2 pieces curry puff
1 glass soy bean milk
Lunch
2 cups rice
1 piece chicken/fish
1 bowl mixed vegetable soup + soy bean curd
1 cup lettuce and cucumber
1 glass plain water
1 banana
Afternoon Tea
1 cup green beans porridge
1 cup tea
Dinner
1 bowl noodle soup (with chicken/beef, fish ball, and vegetables)
1 piece guava
1 glass plain water
Supper
3 – 6 pieces biscuits
1 glass low fat milk

 

What is the recommended meal pattern before a sports event?

  • The goal of the pre-event meal is to prevent you from feeling hungry before or during a workout or competition as well as to maintain optimal blood sugar level.
  • The main dietary goal is to provide high carbohydrate foods, especially complex carbohydrates, with moderate amounts of protein and small amounts of fat.
  • How much food to be eaten will depend on how much time is available before the event/practice session starts. Below is a sample of a meal/snack pattern :
Meal/Snack
Timing
Examples
Snack
½ – 1 hour before 1 – 2 slices bread
Plain water
Light Meal
2 – 4 hours before 1 set tuna sandwich
1 slice papaya
Plain water
Heavy Meal
4 – 5 hours before 1 ½ – 2 cups rice
1 piece roasted chicken/fish
½ cup cooked vegetables or
1 cup raw vegetables
Orange juice

 

What is the recommended diet after an event?

  • Eating or drinking carbohydrate immediately after an exercise session and again after 2 hours may optimize the replenishment of glycogen in the muscles. This means you should drink a high-carbohydrate beverage immediately after the workout and eating a high carbohydrate meal within the next two hours.

Does an adolescent athlete need extra protein?

  • According to the Recommended Nutrient Intake for Malaysia (RNI), the recommended protein requirement of an adolescent is between 1.0 to 1.2 g per kg body weight per day.
  • Athletes who are just beginning a training program should consume 1.0 to 1.5 g of protein per kg body weight a day. Whereas endurance athletes may need 1.2 – 1.4 g per kg a day. For example if your weight is 60 kg and you are just beginning training, you need 60 – 90 g of protein a day. By taking 2 glasses of milk, 2 to 3 pieces of fish or chicken, 2 slices of cheese, two slices of soy bean curd and 1 cup of chickpea or green bean, a day, your requirement of protein is met.
  • Remember, eating more than the recommended amount of protein does not make the muscle stronger or larger. Protein in excess of total energy needs will be stored as fat, not as muscle. Consuming too much protein, whether from food or supplements, can lead to dehydration and weight gain as well as  increased calcium loss from the body.

Why fluid is important for adolescent athletes?

  • Fluids play a critical role in maintaining the health and optimal performance of the adolescent athletes.
  • One of the most important functions of water is to cool the body. As you exercise, working muscles generate heat and this raises the body temperature. Increased body heat makes the body sweat and as the sweat evaporates the body is cooled. If this sweat is not replaced by drinking more fluids, the body’s water balance will be upset and the body may become dehydrated.

How much fluid is needed to prevent dehydration?

The table below gives a general recommendation for fluid intake to prevent dehydration. However, this recommendation may vary according to environmental temperature, humidity and type of sport.

Time
Fluid amounts
1 – 2 hours before event 300 – 400ml of cool water (10°C – 22°C)
10 – 15 minutes before event 300 – 350 ml of cool water
During exercise 100 – 200 ml of cool water
After exercise 350 – 700 ml of cool water

 

Does adolescent athlete need vitamin and mineral supplements?

  • Although vitamin and mineral supplementation may improve the nutritional status of persons consuming inadequate amounts in the diet, no scientific data support the general use of supplements to improve athletic performance.
  • Supplements can give young athletes a false sense of security and any performance improvement will be credited to the supplement and not to hard work and practice.
  • Get the advice of your doctor before deciding to take any vitamin and mineral supplements.

References:
Jamie Stang, Mary Story, 2005. Guidelines for Adolescent Nutrition Services. Center for Leadership, Education and Training in Maternal and Child Nutrition, University of Minnesota. Page 1 – 206.

 

Last reviewed : 20 April 2012
Writer : Zalma bt. Abdul Razak
Reviewer : Tn. Hj. Ridzoni bin Sulaiman

 

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