Nutrition is an integral component to success in endurance sports. Below, Coach Greg weights in on important vitamins & minerals, hydration, and which gels to use (and which to stay away from!).
NUTRITION: VITAMINS & MINERALS
As an endurance athlete, you are probably concerned about taking extra vitamins and minerals for optimum health and performance. You might often find yourself questioning what vitamins and minerals are important, and when exactly are you suppose to take them. As an athlete, you look for foods that have the highest quality of nutrients in them, but advertising companies suggest that additional daily vitamin and mineral supplements are necessary for maximum training. So do you really need supplements if you are eating the right foods? There is hasn't been any research concluding that taking in "extra" amounts of vitamins and minerals will increase your performance, however, correcting vitamin and mineral deficiencies will improve your overall fitness. All vitamins and minerals are essential, but there are those that are most crucial to endurance athletes.
Vitamin C: Vitamin C is also a water-soluble vitamin, and highly important to endurance athletes. Vitamin C is a powerful antioxidant and is valuable for the formation of scar and connective tissue. It is also important for releasing certain hormones and neurotransmitters that are used while exercising. Vitamin C is key in the formation of red blood cells and iron absorption. Vitamin C is imperative for peak performance, and a deficiency in Vitamin C can weaken your ability to perform. Vitamin C is found in easily attainable fruits and vegetables. An abundance of Vitamin C does not enhance your training ability. However, because intense training puts a lot of stress on your body, moderate quantities above the recommended daily allowance (RDA) is helpful to endurance athletes. RDA: 60mg
Vitamin E: Vitamin E is a fat-soluble and also important because of its function of an antioxidant. Vitamin E is popular among athletes because is protects muscle cells from harm, and repairs damaged cells. It also prevents the oxidation of unsaturated fats in cell membranes. Vitamin E deficiencies are uncommon, because it is stored in the body. You can also get Vitamin E from whole grain products, nuts, wheat germ and oils such as corn, sunflower, and soybean. RDA: 30 IU (International Units)
B Vitamins: There are eight B Vitamins: Thiamin (B-1), Riboflavin (B-2), Pyridoxine (B-6), Niacin, B-12 , Folacin (Folic Acid), Biotin, and Pantothenic Acid. The B-Vitamins are known as the "energy" vitamins. They process energy through carbohydrates and are important for a healthy nervous system. The B-Vitamins are water-soluble, and are not stored in your body in large quantities. They are easily excreted, however, too much may cause harm. If you eat the recommended allowances of beans, legumes, whole grains, nuts, fruits, and vegetables, you should not have a B-Vitamin deficiency. However, vegetarians need to be aware, because B-12 and Riboflavin come mainly from animal products. If you consume milk and eggs you should meet the daily requirements. However, if you are a vegan you'll need to look for foods that have been fortified with the B-12 Vitamin or take a B-12 supplement. Vegans can consume enough Riboflavin from eating plant sources such as green leafy vegetables, wheat germ, avocados, soybeans, and enriched grain products. RDA: Thiamin (B-1): 1.5 mg; Riboflavin (B-2): 1.7 mg; Niacin: 20 mg; Pyridoxine (B-6): 2 mg; Folacin (Folic Acid): 0.4 mg; B-12: 2.4 mcg; Biotin: 30 mcg; Pantothenic Acid: 5 mg
Calcium: Calcium is always in demand, especially for endurance athletes. Calcium is essential for all types of muscle contraction; cardiac, muscle, and skeletal. It also is important in structural functions such as bone formation and the synthesis and breakdown of liver and muscle glycogen. Calcium plays a role in blood clotting, hormone secretion, and nerve impulse transmission. Calcium can be lost through sweat during vigorous bouts of exercise. Therefore, and adequate amount is suggested to maintain optimal performance. Vitamin D works in conjunction with Calcium as is aids in calcium absorption. Dairy products offer a significant source of calcium. If you are lactose intolerant look for lactose-free dairy products, or take lactase supplement enzymes. Vitamin D enriched foods are a little harder to come by. Look for milk, juices, and cereals that are fortified with Vitamin D. Fatty fish and egg yolks also contain amounts Vitamin D. As we all know natural sunlight can also provide Vitamin D. However, as we age, we are less able to convert sunlight to Vitamin D. Lucky for us, weight-bearing exercises such as running and weight training also increases calcium adsorption. There are factors to look out for that can decrease calcium absorption, such as too much caffeine, alcohol, excessive sodium and protein. RDA: Calcium: 1,000 mg; Vitamin D: 400IU
Iron: Iron is a major component of hemoglobin and myoglobin. Hemoglobin is responsible for transporting oxygen in the blood, and myoglobin is responsible for transporting oxygen in the muscles. Iron is also required for muscle enzymes involved in metabolism. A deficiency in iron can impair athletic performance. Low levels on iron can lead to anemia, which in turn, causes fatigue that can lead to poor exercise tolerance. Athletes, especially women, need to be aware iron deficiencies. Those who are at risk for deficiency are regular to heavy menstruating females, low body weight athletes, and long distance runners. Extra iron is unnecessary in non-deficient athletes. However, more iron may be useful when training intensity and duration is increased due to the altering of blood volume and muscle mass. Iron is found in lean meats and poultry, and plant foods such as beans, wheat germ, prunes, and spinach. Eating Vitamin C rich foods with high iron foods also increases iron absorption. RDA: 18 mg
Zinc: Zinc controls the activity of enzymes linked to energy metabolism in cells, and is involved in protein synthesis. Zinc also keeps your immune system healthy and helps the healing of wounds and injuries. Zinc has several important functions related to athletic performance, and exercise has been shown to increase zinc loss. However, you should use caution with zinc supplements, because of its side effects, which include the lowering of HDL levels, the "good" cholesterol. Sources rich in zinc include red meat, oysters, turkey, lentils, wheat germ, and lima beans. Zinc is better absorbed through animal foods than plant foods. RDA: 15 mg
As serious endurance athletes, chances are you making the right food choices, rich in a variety of vitamins and minerals. However, we do care about our bodies and do not want to be lacking in any aspect of proper nutrition. Many of you probably take a multivitamin-mineral supplement. Although food is the best source of vitamins and minerals, multivitamin-mineral supplements may be just what you need to give your health that extra boost, especially during intense training. There are some athletes who may need to take specific supplements for vitamin or mineral deficiencies that food, or a multivitamin mineral supplement cannot correct. Those individuals are athletes who are vegans or vegetarians, at risk or osteoporosis, have food allergies, on a restricted calorie diet, or are pregnant. A multivitamin mineral supplement providing the recommended daily allowance should be safe. However, use caution when taking specific supplements due to the dangers or overdosing. If you think you are deficient in a certain vitamin or mineral, talk to your doctor before taking any supplements for the recommended dosage.
NUTRITION: FLUIDS
Fluid is a crucial component of endurance training. As little as one percent of fluid loss can be detrimental to your performance. Between 50-60 percent of our total body mass is made up of water, and 70-75 percent of our muscles comprise of water. Fluids, specifically water, is the main component of blood. Blood transports nutrients and oxygen to our cells. Muscle glycogen also holds a large amount of water, and the water helps remove lactic acid from exercising muscles. Fluids act as shock absorbers in the joints and around the brain and spinal cord, lubricate the digestive tract.
At rest, urine excretion represents the greatest amount of fluid loss, however, during exercise our greatest loss is through sweating. Fluids also aid in the temperature regulation of our bodies. As our body temperature heats up during exercise, we sweat to cool our bodies. The warmer our bodies get, the more we sweat. The more we sweat, the more fluid we lose. Sweating during training can result in a fluid loss, especially for an endurance athlete. Exercising in warm or humid weather, dry climate, or at altitude can increase fluid loss. Anywhere from 16-48 ounces of sweat an hour can be lost during training. Blood volume decreases while sweating, placing greater demands on your cardiovascular system. This reduces your ability to use oxygen. When fluid loss is not replaced, your body temperature increases and exercise becomes harder.
It is essential that your drink a minimum of 8-10 cups of fluid for normal functioning. During each hour of exercising you should be drinking at least 16 ounces. To ensure adequate hydration during exercise, drink 24 ounces of fluid two hours before exercise, and 8-16 ounces 30 minutes before exercise. About half of your fluid intake should be water, but you can also hydrate yourself by drinking non-caffeinated beverages. You can drink caffeine in moderate amounts, but you need to be careful that you don't overdo it. Caffeine acts as a diuretic, increasing urine excretion, which can lead to dehydration. Excess caffeine can also interrupt your sleep patterns.
As you can see, fluids are a key element during your training. Unfortunately, being thirsty is not a good indicator of how much fluid your body requires. Some early signs of dehydration are tiredness, headaches, dark colored urine, and increased heart rate. Fluid intake should be monitored throughout the day, not just during training, for endurance athletes. Not meeting your fluid needs can greatly damage your performance. During your training, experiment with different amounts and kinds of fluid. Pay attention to what makes you feel "good" during your workout. This will tell you what and when you need to drink during race day.
NUTRITION: GELS, PART I
Many of you may have read a syndicated article that studied endurance athletes' preferences of different "energy gels". The article* discussed several brands but limited the "test" to only a few and focused on their results solely on taste or flavor.
Endurance athletes realize flavor is an important issue in picking a supplement, but more primary than taste are ingredients. Interestingly, not even the highest-rated gel scored very high on. This demonstrates that while taste is important, both the energy gel manufacturers and athletes realize the purpose of the gel is the most important issue. To the point, very few of these gels actually taste "good", but they do a good job.
Endurance athletes have long taken supplements to ease the burden of eating directly after a workout or while competing. Energy gels, consisting of a disposable pouch filled with a sugar combination first appeared in the late 1980s and caught on big by the early '90s. In the early years the gels were strictly a simple sugar such as glucose or fructose. These sugars are great for a quick pick-me-up and last about 20 minutes.
The problem, however, with simple sugar-based gels is threefold: 1) They can cause gastric distress; 2) they cause a spike in insulin; 3) and, once you consume one, you need to keep them coming so you don't bonk (exhaust yourself) even harder.
In the last 3-4 years, energy gel manufacturers have started producing gels with more complex sugars like maltodextrin (made from natural corn starch) or even modified complex sugars like galactin (a gummy carbohydrate that yields several sugars upon decomposition). These sugars are less refined and cause a slower release of insulin, avoiding a spike in blood sugar levels and keeping your blood sugar stable.
In summary, the newspaper article neglected to answer the most important questions about gels: Why purchase certain brands and what is in them? Next time, we will investigate the ingredients in different types of gels and discuss how to choose a product that works for you. Using this information, you can narrow your search for a product and find a flavor to suit your taste buds, too.
*The Seattle Times, Nov. 8, 2004, "Marathoners: Going for the goo?"
NUTRITION: GELS, PART II
Following up on the piece above on energy gels, this discussion turns to their nutritional value and deciding which one will work the best for you. Gu, PowerGel, Crank e-Gel, Hammer Gel and Clif Shot are some of the most popular gels and, surprisingly, more similar nutritionally than you might expect.
Calories
First, we do a review of their calories. Simply put, calories are the amount of fuel (not what kind, but how much) you are giving to your body. Most of the gels have 120 or fewer calories. Hammer had the fewest at 91 and Crank had the most at 150. So, for someone who needs more bang or who weighs more, Crank might be for you.
Carbohydrates
Most gels have around 25 grams of total carbohydrates except for Crank at 37. Total carbs indicate how many sugar molecules you are getting. The types of sugars (simple or complex) used in the product are important, too. A quick scan of the ingredients shows all five gels are made with complex sugars (good stuff) as the first ingredient, specifically maltodextrin.
But what about simple sugars?
This question reveals some interesting results and might be the best indicator of which gel you want. Products low in simple sugars help balance your insulin release. PowerGel, Clif and Crank have between 7-8 grams of simple sugar. Remember, though, that Crank has more total sugar so the percentage of simple sugar is actually substantially lower. Gu has 3 grams of simple sugar and Hammer has the lowest with 2 grams. From a percentage standpoint, Crank still has twice as much simple sugar as Hammer.
A final analysis of the sugar content reveals that Hammer has the lowest amount of simple sugar and Clif Shot has the highest. What does this mean? For endurance events, Hammer should cause a slower release of insulin in your body, preferable for long events. For shorter events, say a 5K, you might try Clif Shot.
Electrolytes
Electrolytes (electrically charged salts, including sodium, potassium and calcium) are the things that keep our muscles and heart functioning smoothly. In hot weather and times of stress it extremely important to keep your electrolytes balanced. Different people lose different amounts of electrolytes, but we all lose more in heat and with prolonged exercise. Crank was heads and shoulders above the rest in electrolytes. It contains between 9 and 7 times what the other 4 contain in sodium. It also has almost twice the potassium of the other gels. If you are going long, racing in heat or have a problem with cramps, Crank might be the one for you.
Protein
Which energy gel has the most protein? The answer: They all have zero grams because the products are less for recovery and more for sustaining your energy during an event.
With this nutritional overview you can hopefully make a more informed decision about what you want to use and when. It's surprising that all of the gels' first ingredient was maltodextrin! It looks like the writing is on the wall and energy gel companies see that endurance athletes want something for the long haul.