Myths and Facts

	You should take vitamin and mineral supplements for extra energy and strength during heavy physical activity like athletic competition and military training. Vitamins and minerals do not give you energy or strength. Energy means calories, not get-up-and-go, and vitamins and minerals themselves have no calories. Carbohydrates, fats, and proteins provide energy. Vitamins and minerals help your body get the energy it needs from carbohydrates, proteins, and fats. Weight training or resistance training builds strength.
	Drinking cold liquids during exercise causes cramps. Not at all. The cause of cramps is thought to be related to dehydration - a lack of fluid rather than too much. Cold drinks (40 to 50° Fahrenheit or refrigerator temperature) are the optimal beverages during physical activity because they leave the stomach more quickly than warm liquids.
	You can condition your body to go without water by not drinking during physical activity. Your body does not adapt to lack of water. It does the opposite - it heats up and slows down, just like a vehicle with an overheated engine. Not drinking during physical activity is dangerous. If you go without water during activity you become dehydrated. Dehydration can cause fatigue, dizziness, headaches, weakness, and inability to walk. Severe dehydration can lead to heat stroke, kidney failure, and even death.
	You need to drink only when you are thirsty. Thirst does not tell you when you need water. By the time you feel thirsty you are already dehydrated. You should drink before, during, and after physical activity to keep your body well-supplied with water. In extreme weather conditions, such as heat, cold, and altitude, you need more water more often than you do in a temperate climate. Water is your most important performance nutrient. When your body gets low on water your endurance, stamina, speed, and concentration are weakened.
	Sports beverages and performance drinks are always better than water for performance. Water is always appropriate for fluid replacement. For exercise sessions lasting less than 60 minutes, sports drinks offer no advantage over water except in taste. However, for hard exercise lasting over an hour, sports drinks do have a performance advantage, because they provide carbohydrates to fuel working muscles and your brain.
	It's important to take protein supplements if you want to increase the size and strength of your muscles. Protein supplements do not increase the size or strength of muscles and the amino acids in these supplements are not superior to the amino acids found in food. What does increase muscle size is training, extra calories from carbohydrates, and some additional protein. You can easily get that extra protein from food. Tuna fish, chicken, lowfat milk, lowfat cheese, and instant breakfast powders are excellent sources of protein. For example: to gain 1 lb. of muscle in a week, each day you need an additional 400 calories plus 14 grams of protein, the amount in 2 ounces of meat or 2 glasses of milk. Since most Americans already eat far more protein than they need, this 14 grams of protein is already in your diet. If you take in too much protein, your body can't use it. Excess protein is stored as fat.
	Carbohydrate loading can improve performance for all physical activity. Carbohydrate loading - eating many more carbohydrates than normal while tapering your physical training several days before an endurance activity - is not recommended for events lasting less than sixty continuous minutes because it does not work. Your liver and muscles are able to store enough glycogen to last 60 minutes or more of physical activity. Therefore, carbohydrate loading for exercise lasting less than 60 minutes would not be helpful. Eating a consistent diet that is 55-65% carbohydrate will allow you to replace muscle glycogen stores on a daily basis and will give you the energy to perform well in almost all military activities.
	Salt tablets are needed to replace sodium lost in sweat while exercising. While a little salt is lost in sweat during physical activity, this loss rarely needs to be replaced during exercise and can be adequately replaced by regular meals. Only when you are sweating profusely for several hours and not eating should you be concerned about replacing salt. In these situations, drink a commercial sports drink or a dilute salt solution. Salt tablets are too potent and dangerous. They increase your water requirement and soak up body water that should be going to your muscles.