A Quick Guide to Sports Nutrition

Nutrition for Sports

Specialized exercise training is an integral part of sport performance and proper nutrition is an important component of the total training program, allowing for optimal growth and development in athletes. Sports nutrition for athletes is similar to essential nutrients needed by a non-athlete person with varied increases in their calorie needs from macronutrients and micronutrients.

Therefore, nutritional needs before, during and after exercise should be maintained for optimal sports performance.

Nutrition Assessments in Athletes

Nutrition status of athletes can be assessed by ABCDE method as follows:

A- Anthropometrices (measurement of weight and height)

B- Biochemical analysis (blood and urine test)

C- Clinical signs and symptoms of excesses or deficiency

D- Diet history to assess what a person is eating over a period of time

E- Economic status is assessed for additional factor that should also be taken into account

Note: A study reported by National Institute of Nutrition (NIN) suggested  that 7 days dietary records are necessary in case of athletes in each of the training phase ( pre-event and event phase including post-event phase) as the training duration and intensity vary considerably vary from day to day.

What are the Basic Nutrients:

Dietary pattern of athletes is influenced by many factors such as meal time, food sources and frequency. The nutrients in the food provide energy for every cell in the body, growth and repair of tissue, maintenance of metabolism, and provision of water for every cell.

A well-balanced diet with appropriate amounts of macronutrients (carbohydrates, protein and fat) and micronutrients (vitamins and minerals) is important to provide enough energy for proper growth and activity. Fluids are also essential for hydration supports growth and better athletic performance.

Macronutrients: 

Body needs a large quantity of macronutrients (carbohydrate, protein and fats) on daily basis and have a caloric value.

Calorie is defines as amount of heat required to raise the temperature of 1 gram of water by 1 degree Celsius.

Carbohydrate:

Carbohydrate is main source of fuel for working muscles and make up to 50-60% of your diet. Each gram of carbohydrate provides 4 k cal of energy.

A minimal daily amount of carbohydrates recommended for an athlete is 250-300 grams if the total intake is 2000 k cal (WHO)

Carbohydrate Loading

The aim of the carbohydrate loading phase is to increase muscle’s capacity to store glycogen above their normal level. As certain endurance events (< 90 min) (such as marathon running, endurance swimming and triathlon) require additional amount of glycogen storage to be
spared during the events.

In such events appropriate carbohydrate loading method may be adopted if the carbohydrate stores are below normal.

Note:  Recent studies have reported that as along as the intake of carbohydrate is within the recommended levels, carbohydrate loading technique is not desirable because it will limit intake of other essential nutrients which are required for optimal performance.

Protein:

Protein are needed for proper growth and repair of tissue. Each gram of protein provides 4 K cal of energy. For a healthy individual  diet should contain approximately 10-15% of protein.

Protein Calculation:

The Recommended Daily Allowance (RDA) for protein for:

  • Sedentary people- 0.8 grams per kilogram of body weight
  • Endurance athletes-1.2 to 1.4 grams per kilogram of body weight
  • Strength training- 1.2 to 1.7 grams per kilogram of body weight

Calculating Protein Requirement for a Person Weighing 70 Kg.
RDA for Protein = 0.8 gm of protein / kg of healthy body weight/day
Therefore a 70 kg person needs:
70 kg ( 0.8 g protein = 56 g protein/day)

Fat:

Fats are concentrated source of energy and each gram of fat provides 9 K cal of energy. For a healthy individual  diet should contain approximately 30-35% of fat. Fats can be classified into 4 categories as follows:

Monounsaturated: Olives, rapeseed oil, nuts, avocados, canola
Polyunsaturated (Omega-3) Salmon, mackerel, trout, walnuts, flax seeds
Polyunsaturated (Omega-6) Sunflower seeds, wheatgerm, soybean, corn

Saturated: Butter, cheese, meat and meat products, full-fat milk, pastries, coconut oil and palm oil
Trans fatty acids: Baking fats like hydrogenated vegetable oils (Vanaspati), fatty meat

Micronutrients:

Vitamins and minerals are termed as micronutrients needed in small amount on daily basis needed for-

  • Proper metabolic functioning of the body
  • Prevention of free radicals and
  • Boosts immune function

Water and fat soluble vitamins and inorganic trace minerals are required in small  amount in the body but they contribute in the vital metabolic
functioning responsible for energy release in the body.

Need of Hydration

Fluids vital to the life of every cell in the body. It is a-

  • Solvent
  • Lubricant
  • Medium for transport and
  • Temperature regulator that makes up the majority (about 2/3) of our body and yields no energy.

Pre-event Hydration:

1. Athletes should consume 1.5 to 3 L of fluid above their normal intake the day before the event.
2. Athletes should consume 0.5 L of water 1-2 hours prior to the event and 0.6L of water / other fluids 10-15 minutes before event.
3. Empty their bladder 15 minutes prior to the event is a must.
4. Athletes should drink cool water during the event as it is absorbed faster and cools the body better than water at room temperature.

During Event Hydration:

1. Athletes should drink 150 ml to 250 ml every 10-15 minutes to maintain fluid balance.
2. Athletes should sip the water, and not gulp it down.

After activity Hydration:

  1. Begin immediately to compensate loss in body weight
  2. Athletes can sip plain water, diluted fruit juice and electrolyte glucose drinks

Example of Pre-event Meals

Pre-event Meals: Less than 1 hour Before Exercise (100 K cal approx)

  • Sports Drink
  • Half of energy Sports Bar
  • Fresh Fruits such as banana or orange slices
  • Canned Fruits
  • Dried Fruits
  • Salads & Soups

Pre-event Meals: Less than 1-2 hours Before Exercise (300-400 K cal approx)

  • Fruit flavored yogurt
  • Fresh Fruits like apple, papaya or pineapple
  • Cereal Bars
  • 1 Sports energy bar
  • Milk shake/ fruit smoothie with berries, banana, 1 scoop soy or whey protein
  • Breakfast cereals with milk or oats shake

Pre-event Meals: Less than 3-4 hours Before Exercise (700 K cal approx)

  • Cottage cheese on toast
  • Baked potato with grilled chicken
  • Bread roll with cottage cheese/ meat filling and a banana
  • Pasta with baked vegetables
  • Fruit salad with scrambled egg whites and toast
  • Glass of milk with 1 fruit

Role of Sports Nutrition:

Sports nutrition assumes critical importance because it permits the athlete
to achieve the maximum possible physical performance and is adequate
to cover energy expenditure, and for tissue maintenance, repair and growth. The nutritional needs differ from individual to individual based on
age, sex, body size and composition, occupation, physiological condition etc.

It is essential to take into account all the factors like (physical, physiological, sport specificity etc.,) in recommending dietary allowances not only
to improve the ultimate performance in each individual athlete, but also to achieve desirable body size and composition suitable to the event.

In addition, the post event dietary needs of athletes are also important for repair and regeneration of the tissue and replenish the glycogen stores.

Muscle building Supplements:

Muscle building Supplements include amino acids, creatine, HMB, protein, protein fortified beverages and bars.

Protein or amino acid supplementation in the form of powder or pills should not be taken into large amount as it may lead to dehydration, weight gain, stress on liver and kidney.

Branched chain Amino Acids (BCAAs):

Branched chain amino acids such as leucine, isoleucine and valine are essential amino acids. Consumption of branched chain amino acids before and after exercise have been shown to increase protein synthesis and muscle gains.

Some research studies reported a significantly greater weight gain in lean mass on intake of 14 gram of BCAAs during 8 weeks of weight training.

Dairy products and meat are excellent source of BCAAs. Other food sources of amino acids like leucine, isoleucine and valine are-

         Amino acids                                  Food Sources

  • Leucine-        Whole wheat, brown rice, beans, soy, nuts, dairy, meats
  • Isoleucine-    Chickpeas, chicken, egg, fish, nuts and seeds
  • Valine-           Grains, dairy, peanuts, soy protein, meat and mushrooms

Sports supplements including vitamin and mineral supplements should be taken only in case of their deficiency and only after consulting a Doctor
and of prescribed potencies to avoid any adverse effect on health.

Research studies suggests that vitamin and mineral supplements are unnecessary for the athlete receiving a balanced diet.

Read more: Post exercise recovery techniques

Reference:

  1. Krause’s Food & the Nutrition Care Process – By L. Kathleen Mahan, Janice L Raymond, Sylvia

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