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What is the difference between calories and Kcal?
A calorie is a unit by which energy is measured. These units of energy are so small that a single food item will have tens of thousands of them. Therefore, to ease calculations, they are expressed in 1000-calorie units known as kilocalories (kcalories / kcal / *Calorie / *Cal). 1 kilocalorie (kcal) is equivalent to 1000-calorie units (*a capitalised version is sometimes used depending on which country the product or information is from).
However, confusion may arise when you speak of energy from foods. You would say 'calories' although the actual measure is kilocalories. If an apple provides 150 kcal (150 000 calorie-units), it is commonly said that an apple provides 150 'calories'.
How are the calories of a particular food calculated?
The nutrients which contribute to the energy values in food are carbohydrates (1g= 4kcal), protein (1g= 4kcal), fat (1g= 9kcal) and alcohol (1g = 7kcal). Therefore, the calories from each of these components make up the total calories of the food.
The total energy available from a particular type of food can also be measured by a bomb calorimeter. This device consists of a closed container in which a weighed food sample is burned in an oxygen atmosphere. The container is immersed in a known volume of water, and the rise in temperature of the water after ignition of food is used to calculate the heat energy generated. However, not all the energy in foods is available to the body cells because the processes of digestion and absorption are not completely efficient. Therefore, the biologically available energy from foods is expressed in values rounded off slightly below those obtained in the calorimeter.
Should I be drinking Gatorade when I exercise?
It is very important that you drink plenty of fluids while exercising to prevent dehydration (when your body doesn't have enough fluid) and to perform your best. It is recommended that athletes drink:
- cups of fluid before exercise
- 1 cup every 10-20 minutes
- 3 cups after exercise
- (1 cup = 8 ounces)
These amounts may need to be higher on hot and humid days, for very intense workouts, or for very tall or muscular athletes. Usually, water is the best fluid for your body. But when you are exercising for longer than an hour, your body has lost some carbohydrate and electrolytes. Sports drinks (like Gatorade or Powerade) are a good way to give your body electrolytes and some carbohydrates while exercising. If you are working out for less than an hour, water and a well-balanced meal after your workout will replace the fluid and energy that your body used while exercising.
Should I carb-load before my games or competitions?
When you are training or competing, your muscles need energy to perform. Glycogen is the energy used by muscles. It is made from carbohydrates and stored in your muscles. Every time you work out, you use some of your glycogen. If you don't eat enough carbohydrates, your glycogen stores are lower and your muscles may not be able to perform their best.
Carbohydrate loading is a technique used to increase the amount of glycogen in muscles. It involves eating extra carbohydrates during the week before a competition while at the same time decreasing training. Carb-loading is intended for marathon runners and is not useful for most athletes. Just simply eating a diet that is high in carbohydrates is enough to build good glycogen stores.
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