Eat to Perform

By: Jeff Cathrea, B.Sc. Kinesiology

One of the most frequently asked topics my athletes inquire about is nutrition. Nutrition of course refers to the intake of nutrients into the body and how the digestive system uses this for energy. Many of my athletes train very hard; invest all kinds of energy to get faster, stronger and more powerful then flush it all away by eating incorrectly. Your body is like a finely tuned machine and it needs the right type and the correct amount of fuel to run effectively and efficiently. If you owned an expensive sports car would you fill it full of cheap gas and forget to replenish its oil and fluid supply? Probably not. Your body is designed the same way, eat correctly and your performance will be at its best, eat poorly and you just might find yourself running out gas or worse, your body needing some repairs.

Carbohydrates are the gasoline of the human body, that is, they are the main source for energy in exercise physiology. These 'sugars' are primarily designed to provide energy to working muscles. The two most common carbohydrates are disaccharides and polysaccharides. Disaccharides or simple sugars can be found in sucrose (table sugar), lactose (dairy sugar) and maltose (alcohol sugar). Polysaccharides or complex carbohydrates contain thousands of glucose molecules.

So which carbos are best to eat? The most simplistic approach is to consume complex carbohydrates leading up to training or competition and to consume simple sugars directly after. The reason for this lies in the rate at which the sugars are digested and absorbed into the bloodstream and stored back into working muscle. Complex carbohydrates generally are slower to absorb into the bloodstream, causing a very gradual constant influx of sugars for the muscles to use as fuel. This is optimal for performance as it reduces the risk of running out of gas. Simple sugars are best consumed directly after training or competition. Because your body has a 2 hour window at which to store the most amount of carbohydrates back into your depleted muscles, it is beneficial to consume sugars that are quick to become digested and absorbed, allowing for a maximal storage phase. Traditionally, healthy sources of complex carbohydrates would include pasta, whole grain breads, brown rice, milk, beans or apples, whereas some healthy simple carbohydrates would include, potatoes, cereal, bagels, raisins and oranges.

If carbohydrates are the fuel of the human body, then protein would definitely be the mechanic. ProteinÕs primary responsibility is to aid in muscle growth and repair. Protein also helps to transport enzymes and hormones as well as other nutrients such as carbohydrates and fats. Good sources of proteins can be found in meat, dairy, beans and nuts. Although protein may be used for fuel, it only becomes utilized if the carbohydrate store has been depleted. This is not advantageous because you do not want your body to use protein for energy that could use to make your muscles bigger and stronger. Because protein is slow digesting and aids in the transport of glucose (sugar) to working muscle, it is best consumed after training or competition. The optimal ratio of protein to carbohydrate consumption after activity is 1:3.

Just as it is important to eat the right amounts and types of foods, it is equally important to consume the adequate amounts of water and fluids during games and training. Your body needs to be properly hydrated before, during and after activity to prevent injury or decreased levels of performance. During heavy exercise or intense games, athletes can lose several litres of water per hour (1-2% of their body weight). This does not seem like much, but break out the calculator and youÕll see that this is a significant number! The best way to monitor hydration status is by body weight and by the color of your urine. If your urine is clear or light colored one hour before activity then your body is more than likely adequately hydrated. If it is dark yellow, has a strong odor or is small in volume you are dehydrated and need to consume water until your urine is clear and of a larger volume.

Remember, thirst is a poor indicator of dehydration, as by the time you feel thirsty, your fluid levels have already been depleted. An athlete should consume at least 500mL of fluid 2 hours before activity, 250mL of fluid every 15 min during activity and 500mL of fluid for every pound (lb) of body weight lost after activity. Sports drinks can be beneficial along with the consumption of water during and after competition as a means of replacing electrolytes and carbohydrates. Caffeinated beverages or alcohol should be avoided as both act to further dehydrate the body.

Finally, remember that this article is intended to make you more aware how you are fueling your body to achieve your maximal performance. If you have any specific questions regarding specific sports nutrition do not hesitate to contact your family doctor or local nutritionist for expert advice. But remember; fuel the machine because when the game is on the line you want to be driving the Porsche 911, not the '79 Pinto.