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Nutritional Health for Women

Nutritional health provides a foundation for optimum fitness, performance, and overall health. Excellent nutrition results in more energy, better athletic performance, and less risk of illness. Poor nutrition can cause poor performance, low energy, mental and physical stress, and greater incidence of injuries. A balanced diet is achieved by eating healthy foods, plentiful nutrients, and adequate calories. Reaching this balance can be challenging, as calorie requirements and weight maintenance are a concern to most women. This is complicated by a confusing number of "miracle" diet and nutrition plans, which can be misleading and unhealthy.

As an active, athletic woman, your body often needs more nutrients than it receives. Most girls and women do not eat enough calcium and also have diets that lack enough iron, zinc, and vitamins D, E, and B, including folate. By knowing your potential deficiencies, you can correct them. You can design your own eating plan with a healthy balance of nutrients, vitamins, minerals, fluids, and adequate calories to enjoy the best food, health, and fitness.

Food Content
The building blocks of foods are carbohydrates, proteins, and fats; however, very few foods are "pure" carbohydrate, protein, or fat. Both natural foods, such as milk, and prepared foods, such as a cheeseburger, are combinations of protein, carbohydrate, and fat. Foods also contain vitamins and minerals, which function in the body as enzymes and regulators of organ and muscle function. Vitamins and minerals are in highest concentration and absorbed best by the body when eaten as they occur naturally in foods.

Balanced nutrition requires eating a wide variety of healthy foods to meet all your needs. Unfortunately, many prepared foods and meals are not well balanced and are high in fats or sugars and low in fiber, vitamins, and minerals. The nutrition profile of the average athletically active female is low in carbohydrates, milk products, red meat, fruits, and vegetables. Understanding the value of these foods or their nutritional equivalents will allow you to correct these deficiencies.

The body needs carbohydrates, proteins, fats, vitamins, minerals, water, and electrolytes on a daily basis to function most effectively. Amounts of carbohydrates, proteins, and fats are measured in grams; one gram is about the weight of a paper clip. Vitamins and minerals are measured in micrograms (mcg), milligrams (mg), or international units (IU). The Food and Drug Administration, through much nutritional research, has standardized Reference Daily Intakes (RDI). Formerly called Recommended Daily Allowances (RDA), these guidelines help to set standards for meeting your nutritional needs to optimize health.

Carbohydrates
Carbohydrates are the best fuel source for muscles, brain, and blood. They are broken down by the digestive system into glucose, which is either stored or released directly into your bloodstream to provide energy for the body. Sugars are the simplest forms of carbohydrates; simple sugars include glucose, sucrose, and fructose. More complex carbohydrates, including starches and fibers, are simple sugars that are bonded with each other. Fiber is an important carbohydrate nutrient; insoluble fiber is not digested but is essential for transporting waste out of the body.

Foods that are primarily carbohydrates include fruits and vegetables, breads, pasta, cereal, and "fat-free" desserts and candy. Reading the food label of a package gives you information about total grams of carbohydrates, including the breakdown of sugar and fiber content. Carbohydrates contain four calories per gram; one gram equals about a quarter teaspoon of sugar.

The Importance of Carbohydrates to Athletes
Glucose is stored in the liver and muscles as glycogen. When the body needs fuel and does not have enough glucose in the bloodstream, it converts this stored glycogen to glucose, which travels in the blood to where fuel is needed. Glycogen is always the first source of energy, and for athletes, is the optimal source of energy, especially during competition or an event. The glycogen-to-glucose breakdown is a simple, quick body process. To improve performance, athletes try to maximize the amount of glycogen their body has available. Glycogen storage can be increased before an event by "carbo-loading". The total body storage capacity of glycogen is about 1,500 to 2,000 calories (Kcal)—basically enough energy to live off of for one inactive day or to carry you through 60 to 90 minutes of intense aerobic exercise. It is recommended that girls and women eat at least 55 percent of their calories as carbohydrates, which can be obtained from healthy servings of fruit, vegetables, bread products, and whole grains or beans. Dairy products also contain carbohydrates. Like all foods, however, there are best, good, and poor types of carbohydrates. Best types of carbohydrates are broken down to glucose more slowly and also contain healthy fiber.

Lately, high-carbohydrate diets have received bad press due to the popularity of "high-protein/low-carbohydrate" diets. This is unfortunate. Research in medicine, nutrition, and exercise physiology repeatedly shows that carbohydrates provide the best fuel for life and athletic performance. Diet plans have been compared, and over the long term, weight is best maintained with high-carbohydrate diets.

The Glycemic Index
Glycemic index, or GI, is an index given to mostly carbohydrate foods based on how quickly they raise blood sugar levels. The index is a number from 0 to 100; the higher the number, the quicker the food reaches the bloodstream as glucose. Sugar has the highest glycemic index (100); soybean one of the lowest (18). Foods with a high glycemic index are often processed, starchy, and sugary foods, although some natural foods, such as honey and watermelon, have high indexes. Foods that contain fat or fiber along with the sugar have lower indexes because the fat and fiber slow the release of glucose. Athletes in particular can use the glycemic index of foods to determine which types of carbohydrates provide the best fuel before and during events and training. High glycemic index food products such as GU or Cliff Shotz or drinks such as Gatorload or Endurox provide quick sources of energy and are useful in long endurance events in which the body has depleted its glycogen supply. High glycemic index carbohydrates need to be eaten frequently during endurance events lasting more than two hours to maintain blood glucose levels and provide energy. Before competition, low to medium glycemic index foods are recommended to promote steady blood glucose over the next one to two hours.

Research has recently suggested that people who regularly eat high glycemic index diets have a greater risk of diabetes, obesity, and heart disease due to a tidal wave of high and low blood sugar levels. High GI foods send a sudden flood of glucose into the blood, which causes the pancreas to release a large amount of insulin, the hormone that transfers blood glucose from the blood and into storage as glycogen or fat. The amount of insulin released corresponds to the amount of blood glucose; high levels of both glucose and insulin can be dangerous to body organs and increase the risk of diabetes. Also, there is a rebound of low blood sugar, which can cause sleepiness, moodiness, irritability, and, in diabetics, coma. Hunger is felt again sooner after high glycemic index foods are eaten due to this low blood sugar.

In contrast, low and medium glycemic index foods cause a slow release of glucose into the bloodstream. Normal amounts of glucose circulate and low amounts of insulin are released in a steady stream. This keeps blood glucose levels stable and protects the body and brain from the dangerous effects of unstable blood sugars. Mood is also stabilized, as brain glucose supplies are constant. In people at risk of diabetes, with a family history or a history of (gestational) diabetes in pregnancy, eating a low to moderate glycemic index diet will reduce the risk of developing diabetes later in life.

The Benefits of Low Glycemic Index Foods

Learning to prevent large swings in blood sugars to improve a sense of well-being and performance is a valuable lesson in nutrition. A food's glycemic index can sometimes be surprising: white flour, white bread, and white rice have a high glycemic index, but whole-wheat flour, whole-wheat bread, and brown rice have a lower index. Starchy foods such as white potatoes, corn, and carrots also have a high glycemic index, although sweet potatoes, peas, and celery do not. The best way to incorporate the glycemic index into your lifestyle is to purchase a book that lists common foods (refer to "Resources" at the end of this book). The glycemic index of foods can also be lowered by eating them with foods that slow their digestion, specifically fat, protein, or fiber. For example, eating corn with butter or potatoes with meat lowers the glycemic index. You can also lower glycemic index of pastas and rice by cooking them al dente (firm, not overcooked, and mushy). The following is a chart of some common foods. Basically, low glycemic index foods have GIs less than 55, medium are 55 to 74 and high are 75 to 100.

Low GI Foods Medium GI Foods High GI Foods
Oatmeal 46 Power Bar 58 Jelly beans 80
Yogurt, sweetened 34 Ice cream 61 French bread 95
Meat ravioli 39 Raisins 64 Waffles 76
Soybeans 18 Sweet corn 55 Short-grain white rice 76
Milk 30 White rice 60 Corn flakes 87
Black beans 31 Pizza 62 Baked potato 90
Grapefruit 26 Wheat bread 71 French fries 78
Apple 39 Macaroni and cheese 67 Corn chips 76
Sweet potato 46 Croissant 70 Donut 78
Sponge cake 47 Banana 56 Pretzels 85
Fettucini 34 Chocolate 51 Rice cakes 80
Orange 46 Oatmeal cookie 58 Sugar, honey, 100
Peanuts 15 Popcorn 58 Bagel 75
Thin spaghetti 47 Pita bread 57 Watermelon 75

Fiber
A high-fiber diet has been recognized for years for its health benefits. Dietary fiber content is very important to long-term health. In fact, it has been identified as a necessary diet nutrient by the Food and Drug Administration (FDA). Fiber is a natural plant product that helps slow digestion, lowering glycemic indexes of foods. Fiber has also been identified for its many health prevention benefits, particularly reduced risk of breast cancer, colon cancer, diabetes, heart disease, constipation, diverticulosis, stroke, hypertension, and obesity.

The Reference Daily Intake (RDI) for fiber, based on a 2,000-calorie diet, is 25 grams/day. This should be your minimum. Because large amounts of fiber, especially if your digestive system is not used to it, can cause bloating, stomach upset, and diarrhea, increasing the overall amount of fiber in your diet should be done gradually with fiber distributed evenly throughout meals and snacks. Products such as Beano can help with gas and bloating if that is a problem. Eating various sources of fiber daily—such as popcorn, fresh and dried fruits, vegetables, nuts, beans, and whole grains is also recommended. You should also drink plenty of water with fiber, because this will make your stomach feel full for longer. Because of the cleansing effect fiber has on the digestive tract and bowels, avoid high-fiber products the night before, morning of, and during events, unless your body is used to a high-fiber diet.

The Health Benefits of a High-Fiber Diet

Proteins
Proteins are essential for the body to build and repair muscle and tissues and produce enzymes and hormones, which keep the body regulated. Proteins are made up of combinations of several of the 20 types of amino acids. Some of these amino acids can be reused by the body, but almost half of them must be eaten on a regular basis; these are called "essential amino acids." Although proteins are best used by the body as building blocks for muscle tissue and hormones, they can also serve as an energy source if glycogen levels are low. They provide four calories per gram.

Vegetarians, especially vegans (who do not eat dairy, eggs, or fish) tend to have lower protein in their diets, sometimes lacking essential amino acids. In order to fully meet their protein needs, they can obtain complete proteins by combining grains (corn and wheat) and legumes (nuts, beans, and seeds) in their diet. These foods have additional benefits of having cancer- and disease-fighting properties. Vegetarian diets are quite healthy if followed intelligently to make sure protein (and calcium) needs are not neglected. Vegetarians who do not eat fish, dairy, or eggs should eat at least two servings daily from each of these food groups: legumes, grains, and nuts and seeds.

Vegans Must Eat at Least Two Servings Daily of Each of the Following

There are benefits to meat, poultry, and dairy sources of protein, as they have other valuable nutrients. Red meat is the most optimal source of iron, an essential mineral often deficient in active women. It also contains B vitamins, zinc, folic acid, and complete proteins. Actually, many of the nutrients in meat (iron, folic acid, vitamin B6, and zinc) are the same that are lacking most in women's diets. Red meat and fish also contain creatine, a building block of energy molecules. Fish is an excellent protein, as it contains healthy omega-3 fatty acids, which reduce heart disease and stroke, and is recommended to be eaten twice weekly.

Good Sources of Protein

There has been some controversy regarding contaminants such as hormones, antibiotics, and bacterial or viral diseases associated with meat, poultry, and fish sources of protein. Hormones are fed to some chicken and cattle to increase size and decrease fat, and antibiotics are used liberally to prevent diseases. There are no specific dangers to eating these foods in small amounts, but there are some theories that in large quantities they can lead to food allergies or interfere with growth in younger children. If you are concerned about these risks, purchase meats and dairy products labeled "organic"; these are required to be free of hormones and antibiotics. Many milk, egg, and meat products are now labeled specifically as hormone-free or antibiotic-free.

Fish, although one of the healthiest proteins, can also be harmful especially to women planning pregnancy. Certain types of large fish, including swordfish, tilefish, large tuna steaks, and mackerel should not eaten more than once monthly due to their higher mercury content, which interferes with brain development in unborn and young children. These fish should be avoided for the first year prior to planning a pregnancy. Raw fish and shellfish can also transmit parasites and hepatitis A.

Food preparation is another concern. Fully cooking meats is recommended to kill any potential bacteria or diseases and is always recommended when preparing poultry. Eating blackened food is not recommended, as the charring has been linked to stomach and intestinal cancer.

Most girls and women actually eat enough protein, as it is found in many sources other than meat or fish. Tofu, nuts, peanut butter, cheese, milk, yogurt, and dried peas and beans are good sources of proteins. Some whole-grain breads and pastas also have protein. Many food and energy bars now contain protein as well. Athletic and active women require 1.4g to 1.8g/kg/day (.7 to .9 g/lb/day) to make up 20 to 25 percent of the diet. For an average 140-pound woman, this equals 100 to 126 grams of protein daily. (A three ounce serving of chicken contains 30 grams.)

Because most women's protein needs are easily met, there is no need for protein or amino acid supplements. These are expensive, put a strain on the kidneys, and cause dehydration and bone loss. They are also often combined with other chemicals, which can be dangerous.

The Pitfalls of Protein and Amino Acid Supplements

Fats
Fats are a necessary building block of nutrition and are broken down into fatty acids. The most essential fatty acids that must be supplied by foods are linoleic and linolenic acid, essential for transporting the fat-soluble vitamins A, D, E, and K. Fatty acids also help in energy production, the chemical balance of hormones, and nerve and brain function. In the body, fat cushions vital organs, including the eyes, liver, and heart, and also provides insulation against heat loss. Fat is also a very efficient long-term storage site for fuel, providing nine calories per gram.

Fat's bad reputation comes from its high calorie content, which can lead to obesity if eaten in large amounts. Saturated fats found in meat and poultry have a legitimately bad reputation because they contain harmful cholesterol. What contains "bad" cholesterol, however, seems to change almost daily. It used to be thought that eggs, high-fat cheese, and butter fats were very bad for the heart, blood vessels, and arteries. Now these products have been found to also contain healthy fatty acids that are beneficial when eaten in moderation (one egg and one or two servings of butter fat foods a day). The greatest risk of "bad" fats are due to trans-fatty acids and saturated fats, which increase risk of cardiovascular (heart and blood vessel) disease and stroke. Trans-fatty acids found in stick margarine, shortening, and many snack foods are processed oils that become unhealthy in the chemical processing they go through. Saturated fats are found in high amounts in fatty meats, especially pork fat and rinds, beef fat and lard, and chicken fat and skin. Processed meats, including sausages, hot dogs, and pepperoni, should be avoided as much as possible, as they not only contain very high amounts of saturated fats, but also nitrates, a cancer-causing chemical.

Saturated fats can be avoided by choosing lean cuts of meat (sirloin and tenderloin), avoiding poultry skin and fat, and avoiding foods made with lard or beef, pork, or chicken fat. Full-fat dairy products should be eaten in moderation due to their higher content of saturated fats. Butter is somewhat controversial. Because it is a saturated animal fat, until recently, butter was considered unhealthy, and stick margarine was thought to be a healthier alternative. However, current research reveals that stick margarine is actually the worst type of spread (it is a trans fat). In contrast, butter has been found to contain conjugated linoleic acid, a healthy essential fatty acid. Therefore, eating a serving of butter a day is fine and is a much healthier choice than stick margarine. For those with high cholesterol and heart disease, using soft "buttery spreads" containing monounsaturated or polyunsaturated fats is the best choice, especially soft spreads containing plant products that assist in lowering cholesterol. (Take Control, Benecol, Smart Balance).

The most important research has shown that healthy fats, such as omega-3 fatty acids and monounsaturated and polyunsaturated fats, actually protect the heart from disease by raising the level of the good cholesterol, HDL. This makes certain fats some of the heart-healthiest foods. Heart-healthy fats include peanut butter, avocados, nuts, olive and peanut oil, and fish oil. Omega-3 fatty acids have also been shown to prevent some cancers.

Cutting all fats out of your diet is never recommended, especially for active athletic women, because fats are an essential part of hormone functioning, vitamin transport, and disease protection. Fats also promote a feeling of fullness and satisfaction from meals, reduce cravings for unhealthy foods, and allow carbohydrates to be digested more slowly, stabilizing blood sugar levels. Fat-containing foods such as meat, poultry, and dairy products provide natural sources of necessary nutrients especially important to women: iron, folate, and B vitamins in meats and calcium in dairy products. Fats should make up 20 to 30 percent of your regular diet.

Healthy Fats
Classifications Examples
Monounsaturated fats olive, safflower, canola, peanut oils, nuts, seeds, avocados, olives, very lean meats and poultry
Polyunsaturated fats cold-water fish, sunflower, corn, soybean, safflower, flaxseed, grapeseed, cottonseed, sesame, walnut oils, soy products, wheat germ, whole grains

Healthy Fats That Are Good Sources of Omega-3 Fatty Acids

*Sardines, large tuna steaks, mackerel, swordfish, and oysters contain higher mercury and PCB levels; in pregnancy, eat these no more than once a month. (Canned tuna, especially albacore, can be eaten twice a week.)

Unhealthy Fats That Should Be Eaten Sparingly
Classifications Examples
Trans-fatty acids hydrogenated and partially hydrogenated oil, stick margarine, shortening
Saturated fats lard, animal fat, full-fat dairy products, palm and palm kernel oil, coconut oil

Vitamins
Vitamins are organic nutrients that function as enzymes and regulators of important chemical reactions in the body. Vitamin deficiencies can result in diseases and problems with certain body structures and functions. Vitamins are either water or fat soluble. Water-soluble vitamins are not stored by the body, and, therefore, have less risk of overdose and more risk of deficiency. Because fat-soluble vitamins are stored (in fat), it is possible to overdose, causing liver damage. Studies have shown that athletic, active women do not get enough vitamins B, D, and E through their diet.

Type Vitamin Function
Fat soluble A vision, skin, hormones
D bones and calcium
E prevents cell damage
K blood clotting
Water soluble B metabolism
C healing, connective tissues

Fat-Soluble Vitamins
The fat-soluble vitamins include A, D, E, and K. Vitamin A is important for night vision, skin, and hormone regulation and is found in milk, butter, and eggs. Beta-carotene is a building block of vitamin A that has cancer-fighting properties, but only when eaten from food sources. Beta-carotene supplements are not recommended as studies have shown that high doses may actually increase certain cancer risks. Healthy natural sources of beta carotene include leafy greens and orange-colored fruits and vegetables (cantaloupe, squash, carrots, sweet potatoes). Vitamin D is essential to women because it acts as a hormone that aids in bone building and calcium absorption. Vitamin D can be made by your body cells through sun exposure; 15 minutes of direct sun (not through sunscreen or glass) on your face and hands daily will allow your body to make enough. Vitamin D is found in egg yolks, saltwater fish, and liver and is added to most milk and milk products. Vitamin E is well known as an antioxidant that can prevent cancer and prevent cell damage including damage to blood cells and muscle tissue during exercise, so it is important to exercising women. It is found in vegetable oils, nuts, beans, and green leafy vegetables. Vitamin K is important for blood clotting and also regulates calcium.

Water-Soluble Vitamins
Vitamin C is necessary for muscle, bone, and soft tissue health. It also helps wound healing and immunity and is an antioxidant that has cancer-fighting properties. Vitamin C is found in orange juice and citrus fruits, tomatoes, strawberries, and red, orange, and yellow bell peppers. Vitamin C aids the absorption of iron. At least 60 milligrams of vitamin C should be obtained through foods or drinks daily.

The B vitamins are important for energy metabolism. B vitamins are also known as the "stress" vitamins, because the body needs them for repair and higher function in times of stress or illness. Important B vitamins to women are folate, which helps prevent anemia and birth defects in pregnancy, and vitamin B6, which is important to nerves, hemoglobin, and antibodies. B6 can also improve mood and help with PMS. B12 is also important for nerves and blood cell formation. Thiamin, riboflavin, and niacin are involved in energy metabolism and are needed at higher doses also during times of high activity. It is common for active and athletic women to not consume enough B vitamins.

Minerals
Minerals are inorganic chemical nutrients that perform vital roles in the body. The important minerals for women include calcium, iron, magnesium, and zinc. Unfortunately, many women's diets are deficient in these important minerals. Other minerals required in much lower quantities include phosphorus, copper, selenium, manganese, and chromium.

Important Minerals and Their Function
Mineral Function
Calcium bone building
Iron carries oxygen in blood
Magnesium muscles, nerves, bones
Zinc metabolism, growth, immunity

Calcium is one of the most important minerals for women. It is essential not only for bone strength and health, but is also needed for heart, muscle, nerve, enzymes, and blood clotting. Calcium is required by the body as the building material for bones, and low dietary calcium is directly linked to osteoporosis. Because calcium is constantly needed to rebuild bone and also for other body functions, it must be replenished daily. The body loses calcium in nails, hair, skin, sweat, urine, and stool. Athletic women lose extra calcium through sweat, and women on high-protein diets or those who drink several carbonated beverages daily also lose calcium more quickly.

Unless you are a real dairy-product lover, it is tough to get enough calcium without eating calcium fortified foods or taking supplements. Other natural sources include almonds, broccoli, kale, canned salmon, sardines, spinach, and dried peas or beans.

Calcium is available as supplements in compound form, including calcium carbonate, found in antacids; calcium phosphate, found in cereals and food bars; and calcium citrate, the most efficient form of calcium supplement for your body and the type recommended if taken with iron. The recommended amount of calcium for women is 1,200 to 1,500 milligrams a day. This translates to at least four calcium-rich products a day such as yogurt, milk, cheese, or calcium-fortified food. If you are taking calcium supplements, try to take them in the evening in split doses (dinner and bedtime) to promote absorption. If you are taking iron supplements, choose calcium citrate instead of carbonate to improve absorption of both minerals.

It is very important to have a diet with enough calcium. Practical advice for all girls and women is to take one 600 milligram calcium supplement before bedtime to replace calcium-rich foods not eaten during the day. If dairy products are not eaten regularly, try to drink calcium-fortified juices or other calcium products (check labels for content). Calcium also has other added benefits, including easing symptoms of PMS, preventing muscle cramps, and improving weight loss success.

Iron
Iron is involved in all body cell functions. It plays the very important role of transporting oxygen throughout the body in red blood cells. Women are at greater risk of low iron levels due to menstruation; athletes also tend to have lower levels of iron because it is broken down with exertional exercise and lost through the kidneys, digestive system, and sweat. Women should get 18 milligrams of iron daily, and needs go up in pregnancy. The best sources of iron are meat, poultry, fish, eggs, fortified foods, and foods cooked in an iron skillet. Nonmeat sources include wheat germ, whole grains, green leafy vegetables, and dried fruits. There are also many iron-fortified cereals and foods available.

Iron supplements, other than those found in a multivitamin, should not be taken unless prescribed by a doctor. If you are required to take iron supplements, ask your doctor for a ferrous gluconate formula, as this tends to have less constipating and digestive system side effects. Iron absorption is improved when taken with a source of vitamin C and is made worse with caffeine products.

Magnesium
Magnesium helps regulate glycogen (thought to prevent diabetes), regulates body calcium, and aids in muscle, nerve, and body enzyme function, playing a role in preventing fatigue. Magnesium can help relieve muscle cramps and also helps with symptoms of PMS. Magnesium has also been found to prevent hypertension, hardening of the arteries, and can also help prevent migraines. Magnesium is found naturally in hard tap water, spinach, beans, whole grains, nuts, seafood, meats, and chocolate (it can help prevent chocolate cravings in PMS).

Zinc
Zinc helps metabolize nutrients and allows growth and immune function. It also affects hormones. Zinc is needed in higher doses during growth, pregnancy, and with athletic activity. Zinc is found in meats, seafood, and milk products, and absorption is inhibited by fiber; therefore, vegetarians are at particular risk of having low zinc levels. Women should get 12 milligrams of zinc per day.

Water and Electrolytes
Water is essential for life and activity. Water is necessary for transporting nutrients in the blood, digesting and excreting nutrients, providing the structure to your body cells, regulating temperature, lubricating joints and organs, and protecting the brain and spinal cord.

Water must be replaced in large amounts daily and is the number one nutrient needed to survive. Athletic and physical activity requires water; sweating requires more. Dehydration is the term used to describe low water levels in the body. Signs of dehydration include thirst, weight loss, weakness, fatigue, loss of appetite, dry mouth, small amounts of dark-colored urine, headaches, poor concentration, overheating, and, ultimately, whole body collapse.

Water or juices in plentiful amounts is the best fluid source for your body. Water can also be absorbed by the body in foods (soups, melons, and vegetables). It is recommended that at least eight, 8 ounce water or juice drinks are consumed each day, in addition to drinking that makes up for sweat lost during a workout. (For specifics on fluid recommendations during exercise, see chapter 14, "Exercise Fuel.") Caffeine, alcohol, and some stimulants found in "energy drinks" are diuretics and cause your body to lose water (resulting in more urination); therefore, these drinks should not be considered part of your minimum daily fluid needs.

Electrolytes
Because the blood is full of molecules, the correct ratio of molecules to water must be maintained in order to keep the blood flowing and allow for transport of nutrients in and out of cells. Much of this transport follows gradients across cell membranes. Electrolytes facilitate these gradients via chemical interactions between molecules; thus, electrolytes maintain proper body fluid levels and transportation of essential nutrients. Electrolytes are lost through sweat, urine, and digestion and must be replenished daily. Sports drinks are formulated to replenish electrolytes. The most important electrolytes are sodium and potassium.

Sodium is necessary for maintaining water in the blood and for regulating nerve and muscle activity. It is lost in sweat and must be replenished with exercise that lasts more than 60 minutes, or sooner if exercising in high temperatures. Low sodium levels can cause drowsiness, weakness, cramping, and confusion. Endurance athletes who drink water without sodium during long events can develop serious illness. Sodium is found in many natural and most processed foods. Potassium also plays a role in muscle and nerve activation and also functions in glucose transport and glycogen storage. Potassium is lost in sweat; low potassium can cause muscle weakness and fatigue, and in severe cases, affect heart rhythm. Potassium is found in fresh fruits and vegetables.

Special Diets
Special dietary restrictions or limitations require greater attention to nutrition. Medical conditions or illnesses might also require special diets or supplementation. If you experience any of these, consulting a nutritionist is recommended.

Diabetes
Diabetes requires careful maintenance of blood sugar, through blood monitoring and controlled diet. Blood sugar monitoring should be done as recommended by your doctor and also during exercise, especially if the exercise is for more than 30 minutes. You should always have a high glycemic index food available in case you develop hypoglycemia (low blood sugar) and maintain your low to medium glycemic index diet with regularly scheduled meals. The best nutritionist for you is a certified diabetes educator. It is highly recommended you consult a nutritionist if you are diabetic, as your nutritional needs are beyond the scope of this book.

Illness
If you have an illness with fever, you will likely have to replenish the electrolytes potassium and sodium due to sweating. Similarly, gastrointestinal illness causing vomiting or diarrhea requires additional electrolytes; good ways to replenish are by drinking sports drinks. If you are taking antibiotics, increasing your daily intake of yogurt will help protect the normal bacteria in the bowels and prevent you from developing diarrhea. You must take a multivitamin during times of illness, as more vitamins are needed for the body's healing and stress response. An additional B complex and vitamin C can also be helpful. Avoid working out if you have fever, vomiting, or diarrhea.

If you regularly suffer from irritable bowel syndrome or frequent diarrhea, you need to consider replenishing your electrolytes and drink extra fluids. A higher-fiber, lower-fat diet with smaller, more frequent meals can help regulate you.

Lactose Intolerance
Lactose intolerance is the inability to digest lactose, the sugar that naturally occurs in milk and milk products. Babies are born with the enzymes necessary to digest lactose, but some adults outgrow it. With lactose intolerance, diarrhea and gas result after eating dairy products. Diarrhea can cause dehydration and loss of electrolytes, so these should be replenished. Lactose intolerance can be managed through pills that help digestion, such as Lactaid, or dairy products that contain the enzymes. If you cannot eat dairy products due to lactose intolerance you are unable to correct, make sure you are getting calcium through fortified foods and juices, or taking supplements to equal four servings per day. Soy milk is an alternative but is not usually as high in calcium as dairy products, so check the label.

Vegetarian Diets
Vegetarians must be very attentive to their diets, especially the amount of calcium and protein they take in. Although vegetarian diets are high in vitamins and fiber, they tend to be low in iron, calcium, and magnesium. Vegans, those who eat plant products only, must include two servings daily of beans or soy, grains, and nuts or seeds in order to ensure adequate protein combinations. They must also eat calcium-fortified foods or take calcium supplements to fulfill the 1,200 milligrams-a-day requirement.

Pregnancy
Nutritional needs increase in pregnancy. Folate supplements should be taken when planning a pregnancy to prevent birth defects that can develop early in the development of the fetus, even before a woman learns she is pregnant. Most prenatal vitamins contain 600 to 1000 micrograms of folate, more than the RDI of 400 micrograms a day. Calcium needs increase to at least 1,300 milligrams daily and iron to 30 milligrams a day. After the first trimester, calorie needs increase by 300 to 500 calories a day, and more if you are exercising. Protein needs also increase slightly. Fluid needs increase dramatically, and water should be always available.

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From The Active Woman's Health and Fitness Handbook by Nadya Swedan. Copyright © 2003 by Nadya Swedan. Used by arrangement with Perigee, a member of Penguin Group (USA) Inc.

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