Is it ever a wonder that kids get away with eating the darndest things. They gobble candy ice pops, french fries and for the most part remain amazingly thin and fit. However, adults with the same type of diet are high-cholesterol dynamites just waiting for an explosion into triple-bypass heaven. Why do the little brats get to eat what ever they so desire without worry, while adults have to monitor every gram of anything that even considers passing through their lips? Basically, this is because children expend an amazing amount of calories due to their active lifestyles. Have you ever noticed a child walking with his mother in a shopping mall? For every one step that the mother takes, the child must take two in order to keep up, causing him to be in a constant gait alongside the mother. Thus the child is burning much more calories than the mother is. In addition, compare the lunch break of a typical adult versus that of a typical school child. How many adults that you know eat their lunch as fast as possible so that they can play tag for an hour before going back to work? And playing tag for an hour requires more fuel than having an hour discussion on the headline story of Quantum Mechanics Weekly. This is not to say that adults and children have the same physiological makeup and functions that they can be considered completely comparable to one another. However, the two can be fairly paralleled to each other if you just consider the human body's nutritional needs as related to the energy utilized by daily activities. Simply, the more you burn, the more food you need.
And so, with the above premise it can logically be concluded that adults who exercise have greater caloric needs (just as does the child) than the average person. Then how should athletes fill this energy debt? We are told to eat healthy, and stay away from fried foods, chocolate, candies. But, if you're burning the calories, shouldn't it not matter where the calories are coming from?
Actually, not all foods are created equal. It does matter where the calories that you burn come from because your body has certain stores of energy to be utilized during physical activity. Thus the most efficient way to fuel your body during exercise is to eat foods that target these stores. In order to understand how this works, it is important to understand basic digestion.
The food that we eat can be separated into three different categories: carbohydrates, proteins and fats. Carbohydrates, which are located on the bottom of the food pyramid, come from foods such as cereal, bread, sugar, etc. They exist in most foods that we consume and usually thus are the bulk of our diets. When digested, these carbohydrates are broken down by enzymes into smaller molecules: glucose, fructose, and galactose. In the liver, galactose and fructose are converted into glucose. "Glucose may then be stored as glycogen in the liver or may be exported to the skeletal muscles and heart, where the glucose is stored as muscle glycogen if the glycogen stores in those muscles are reduced." (Noakes, 59) Extra carbohydrate is stored as fat in adipose tissue. Though since carbohydrates act as a primary source of fuel for our bodies, most of our fat is found not to be from "extra carbohydrate" but rather from the actual fat that we ingest in our diets.
Fats are digested and absorbed into the bloodstream through the wall of the upper and middle portion of the small intestine. In the form of triglyceride molecules they are transported and stored in adipose tissue. These fat storage sites are found to surround vital organs such as our heart and kidneys. (Noakes, 59) Also these fat storage sites are found in those all-too-familiar places that constantly need work: the stomach, thighs, and buttocks. Fats, unlike carbohydrates, are on the top of the food pyramid. Examples of common foods that contain a large amounts of fat are mayonnaise, butter, oil, and chocolate.
When digested, protein molecules are broken down into simpler amino acids. These amino acids act as the replacement for protein in tissues and muscles that are constantly being utilized by the body. Ingestion of protein from meat, fish, cheese and nuts is important in maintaining a healthy system. While the human body requires all twenty of the existing amino acids, it can only synthesize twelve of them. "When any one of the amino acids is necessary for the synthesis of a particular protein is unavailable, the protein cannot be made..." (Curtis, 728) This can do great harm, especially to an active person who relies on his body's resources to rebuild necessary proteins. The eight amino acids that the human body cannot synthesize are found in sufficient amounts in the everyday foods that we eat, especially vegetables.
Now that we've had a crash course in basic digestion, the next thing that's essential for conscious athletes to understand is how we convert this fuel into the energy allows us to run, bike, swim, and play tag. Adenosine triphosphate (ATP) is a universal energy storage compound. (Purves, G3) When it is broken down into ADP or AMP, energy is released that (among many other things) drives muscle contraction. Carbohydrates provide most of the material necessary to make the ATP that we utilize in our daily activities. The glycogen stored in our liver, through the work of specific enzymes is converted into glucose, which is released into the bloodstream. "During exercise the main site of blood glucose uptake (from the bloodstream) and utilization is skeletal muscle." (Noakes, 61) The glycogen stored in muscle is not directly converted into glucose by enzymes however. Instead it enters a process called glycolysis, and then subsequently, the Krebs Cycle which produces the ATP that drives the action of the sarcomere. The sarcomere is the functional unit of our muscles. It is composed of myosin (thick filaments) and actin (thin filaments), which slide past each other when the muscle is stimulated. "The contraction of the sarcomeres is dependent on ATP in two ways: hydrolysis of ATP by the myosin molecule provides the energy for the cycle (that ultimately results in muscle contraction) and combination of a new ATP molecule with the myosin molecule releases the myosin head from the binding site on the actin molecule (thus "releasing" the contraction of the muscle.)" (Curtis, 875)
Fats are the next most used for energy after carbohydrates, however fats are only used as a secondary source. This is because they must be converted from their state as triglyceride molecules into fatty acids and the enzyme that does this is a "hormone-sensitive lipase." This lipase is inhibited by insulin, a hormone that exists in the bloodstream and is directly stimulated by the consumption of carbohydrates. However, this lipase is stimulated by adrenaline. Once released into the bloodstream, the fatty acids that exist in the free form (that is, not bound to albumin, a blood protein) are taken into the muscle and used in the Krebs Cycle for the production of ATP. If these fatty acids are not needed immediately for energy, they are once again stored as triglycerides, but now in the muscles. "Evidence now shows that these muscle triglyceride stores provide important fuel during prolonged exercise (e.g. ultra running)." (Noakes, 62) This is extremely important because the amount of total-body carbohydrate store in an average person (a 154 lb healthy male) only lasts a little over two hours, while typical fat stores supply almost sixty hours of fuel. (Noakes, 63)
The muscles in our body are made up of the last category of molecules: protein. And while this is the main function of the protein that we ingest, the body can use protein as an energy source under certain conditions. "Under such conditions (e.g. complete starvation, or prolonged exercise with carbohydrate depletion), protein's major role is to provide the liver with substrates from which the liver can produce glucose when the liver glycogen stores are low." (Noakes, 63)
And so, protein, fats, and especially carbohydrates are essential to fuel the body during exercise. But, may other things happens to the body during exercise. Perhaps most important of these is that we sweat. Our sweat contains waste products, electrolytes such as sodium and potassium, and most importantly water. Extreme loss of water causes dehydration, a very serious health threat. Dehydration can bring on "heatstroke, skin blood flow is reduce, and body heat storage decreases." (Noakes, 109) "For some, dehydration becomes chronic and can lead to fatigue, headaches, even muscle cramps." (Applegate, 26)
Salt and Potassium, among other electrolytes, are vital to the human body as well. As a matter of fact, the Sodium-Potassium Pump is one of the most important active-transport systems and is directly responsible for the electrical phenomena that causes nerve impulses. Along with the approximate 1 liter of water lost during running per hour, about two grams of electrolyte is lost. If not replaced, the person can lose many of their motor skills and become disoriented. (Setnes, 51) For Ultra runners this could mean having to leave a race with a DNF.
Thus, obviously, the first and foremost thing that an athlete must remember is that its important to keep hydrated. If an athlete is only exercising for time periods that last less than an hour, water is the ideal means of rehydrating. However, if he is exercising for longer than an hour, he should strongly consider using electrolyte replacements as well.
A popular means of water and electrolyte replacement are sports drinks. These fluids are produced specifically to replace those things that a person's body loses during exercise. Thus, "most sports drinks are blends are carbohydrates (for energy), electrolytes such as sodium and potassium, and water." (Applegate, 26) In addition, what sports drinks have that regular other drinks do not, is that they are dilute. When exercising at a moderate to fast rate, the "blood is shunted away from the stomach to working muscles, which are demanding more oxygen, hence requiring a larger blood flow. With less blood flowing to the stomach, the digestive process will be compromised." (Setnes, 52) Thus, if one ingests drinks high in carbohydrate and electrolytes such as colas and juices, the body will spend the absorption it does transporting and digesting these carbohydrates. This inhibits the more important function of drinks- hydration, for the water is not absorbed straight through into the body. Sports drinks, however, have managed to find a good ratio of water to carbohydrates/electrolytes for both the means of maintaining balanced water, energy and electrolyte level. Yet, while soda and juice are basically not recommended, those athletes, such as ultrarunners, who exercise for extreme amounts of time (and perhaps at a decreased pace), the extra carbohydrates may be beneficial. Caffeinated beverages (e.g. coffee, tea, cola) are not recommended, though, because they are diuretics (i.e. they increase fluid loss from the body.) For the same reason the consumption of alcohol is discouraged.
Now that we've determined that Sports drinks are the ideal beverage for athletes, we find ourselves inundated with a variety of products. Which sports drink on the market is best for optimum performance? Gatorade? Powerade? All Sport? etc,etc,etc. Believe it or not, for the most part, sports drinks are basically the same with very few differences between the different brands. So, it is really up to the consumer to surf the available products and decide what it best for himself. Furthermore, each different flavor has the same basic nutrients, so it doesn't matter to your body whether your taste buds prefer lemon-lime or berry-blue. However, All Sport, in the past year has added something that may give its product a nutritional edge over others. This sports drink now contains B vitamins. "These vitamins perform vital roles in energy metabolism and help maintain healthy circulation. Research shows that we lose B6 during long runs. Since part of the energy we use during long runs comes from the breakdown of protein and since B6 helps with this breakdown, the extra B6 in All Sport will help those who don't get enough of this vitamin." Therefore, if you are an ultrarunner, or do any activity that call for extended periods of exercise, you may want to consider All Sport as your sports drink choice." (Applegate, 28)
But, if all we did take in was sports drinks, our body would be in severe caloric debt. Plus, it's important to energize your body with food beforehand (and in depending on the case, perhaps during and after) if you want to perform well. Many athletes concoct their own recipes. For example, Strolling Jim 40 Record Holder Janice DeHaye counts on candy bracelets and chocolate Pop-Tarts to continually feed her glycogen storage during ultras. (Dehaye, 33) Baked potatoes, bananas, oranges and bagels are all commonly used for the same reason. However, maintaining a stomach that is not "upset" during exercise is often a battle for athletes. This is why they are specially engineered foods that are easy on your stomach, and are made especially to be used by athletes. Among these special foods are energy bars and energy gels.
Energy bars are compact sources of nutrition used by athletes world-wide to replenish their body's energy stores. There are two different types of energy bars on the market: those that are high in carbohydrates (and low in fats and proteins), and those that are a more balanced mix of all three types of foods. Most nutritionists agree that a diet high in carbohydrates (about 70%) may be more beneficial to athletes, but there is no conclusive evidence that supports that this means of controlling diet is any better for performance. Thus, until there is concrete scientific evidence as to the most beneficial of the two types for performance, they will live on as rivals. The makers of the high- carbo bars like Powerbar and VO2 max bar preach that the high carbohydrate ratio in their bars helps with endurance, while the lack of fat makes the bar easier to digest. However, others swear by the type of energy bars made to support a balanced diet. Energy bars like Pr Bar and Balance have only forty percent carbohydrate, and approximately 30 percent each of fat and protein. They advertise that the balance of all three food types in their bars cause the athlete to burn fat during exercise, thus allowing them to save their carbo stores for when they really need it: for a kick at the end of a race.
Basically, if you are interested in eating energy bars, you must chose a type that is particular to your own personal needs. People who are interested in loosing weight, but have had problems doings do in the past because of a high carbohydrate diet may want to consider The PR bar. Many young athletes enjoy power bars because of their ready availability (many other bars are difficult to find) and wide variety of flavors. Each athlete has a basic idea of what food is best for their system before a race, meet, match or practice. It is most important to listen to your own body, because everyone's system takes the stress of exercise and vigorous activity differently.
Perhaps if you find that energy bars sit in your stomach and make you nauseous during long periods of exercise, you may want to consider a different type of food engineered specifically to be used during exercise: energy gel. Gu, first came out in 1994, a product of Dr. William Vaughan's Kitchen Aid. The idea behind the making of Gu (and now many other energy gels, including Power Gel and Relode) was to produce a product that requires an athlete to do little eating and digesting to get the calories and nutrients he needs to maintain his level of exercise. This is extremely important because digestion of solid food during exercise is slowed down (the blood is more busy feeding your muscles with oxygen, than it is attempting to absorb digested food.) Thus, the least amount of bulk put into an athlete's stomach, the less chance he will feel bloating or other stomach discomfort during activity. As a matter of fact, Gu is designed to be taken on an empty stomach (with water.)
Energy gel not only supplies much needed calories to the athlete during exercise, but also many other significant things your body need to carry on the vigorous activity that it is going through. Gu contains about 20 mg of sodium, which is extremely important for those people exercising for a long time (recall that sodium is lost in sweat.) Gu also has leucine and valine in it. These are two of the eight amino acids that your body is unable to produce on its own. The presence of these amino acids not only act as a store of energy for the body during distance runs, but they also help prevent the breakdown of muscle, which occurs when blood levels of amino acids are low. In addition, Gu contains a few interesting things that directly aid the athlete who has been under a large amount of stress due to exercise. Small amounts of ginseng are added for energy, while Chamomile is added as an anti-inflammatory agent , and a small amount of cola nut extract is added for its caffeine. Vitamin E and C are also found in Gu to remove free radicals (which are found in increased measures during exercise.) Also, Gu is one-hundred percent carbohydrates, so it is purely to "recharge" your glycogen stores. The distinction, however, between the carbohydrates found in Gu as opposed to the carbohydrates found in candy, is that Gu is made of a mixture of both complex and simple carbos. Simple carbohydrates (like candy) gives your body a "high" and then falls into a "low." But, Gu's complex carbohydrates are released into the bloodstream at an even and constant rate (not a jerking high/low rate.) So, the athlete feels full of energy during his entire workout.
Gu is a revolutionary step for endurance athletes who have problems getting the nutrients necessary to remain healthy and well nourished during exercise. Next, who knows!?! Perhaps soon ultrarunners will be independent of aid stations. Just imagine a 100K race without any food, and the runners dependant on water pills and energy pills for nourishment. As with today's sports drinks, energy bars, and energy gels, one can never tell what they're up to on the front page of "edible engineering" in our world. But because of this, it is important not to get so caught up in the hype. Energy drinks, bars, and gels are not made to fulfill a person's complete nutritional needs. Carbohydrates in the form of "real food" are just as important to an athlete. So, don't forget to fill up on baked potatoes (or french fries) during meals also in order to fuel your body for optimum performance.