THE PHYSICIAN AND SPORTSMEDICINE - VOL 26 - NO. 9 - SEPTEMBER 98
Many casual exercisers and competitive athletes believe they should avoid food for several hours before they exercise or compete. Others wonder if they should snack, perhaps on an energy bar before a soccer game. And a few are so nervous that even the thought of food is nauseating.
Whatever your concerns, experimenting with some of the following preactivity strategies and finding what works best for you can give you top energy and performance.
Is it bad to eat before exercising or competing? Doesn't the food just sit
undigested?
As long as your activity is moderate (at a pace you can maintain for more than 30
minutes), your body can digest food during exercise. Preactivity eating can help you
significantly by supplying energy for sustained exercise and preventing the
lightheadedness, fatigue, and indecisiveness that can result from low blood sugar. The
food you eat 5 minutes to 4 hours before activity helps fuel your muscles and brain, and
it can help you perform better.
For a few people whose activity is moderately paced, eating causes gastric upset or intestinal problems. If you have these difficulties, you simply have to learn from experience the preexercise eating plan that works best for you.
With intense activities like rowing, sprinting, or speed skating, blood flow is diverted from the stomach to the working muscles. If you'll be exercising or competing intensely, you'll probably want to allow about 4 hours between eating and the event. That's the time needed for a typical meal to empty from the stomach. Otherwise, you may have discomfort or even nausea.
What can I do before a 10 am soccer game?
Carbohydrates are very important for maintaining normal blood sugar (the fuel used by the
brain) and glycogen (the fuel used by the muscles). Because your blood sugar drops as you
sleep, you need to replenish the depleted stores or your morning performance could suffer.
Plan to eat a carbohydrate-based breakfast between 6 am and 8 am; then, if you're still tired, go back to bed. Cereal, bread, fruit, and fruit juice are excellent choices that may help you concentrate better and respond more quickly during that morning soccer game. Or, be sure to eat extra food the day before: Have an extra-big dinner that's low in fat and a substantial bedtime meal or snack. You'll have a better chance of maintaining a high energy level the next morning.
I get so nervous before a competition that I can't even think about eating. What
can I do?
Plan to eat several hours before activity, and eat familiar foods that won't cause a
surprise stomach upset. Many athletes like oatmeal or other hot or cold cereals with
low-fat milk. Other soothing, carbohydrate-rich choices are bagels with a little light
cream cheese, yogurt, pancakes, or French toast. If the thought of solid food turns your
stomach, you may prefer a meal replacement drink.
Any fuel is better than none, so try to consume at least 300 to 500 calories.
I'm so hungry in the afternoon that I buy a candy bar for quick energy before
working out. Does sugar hurt sports performance?
Research suggests that candy doesn't hurt most people's sports performance. In one study,
reported in the March 1987 Journal of Applied Physiology, athletes who ate a big
breakfast 4 hours before and a candy bar 5 minutes before hard exercise improved 20%
during the exercise test compared with when they ate nothing. The results of the study
also suggest that just candy and no breakfast before exercise improved performance 10% in
comparison with eating nothing.
Some people are sensitive to preexercise sugar, however, and have a rebound blood-sugar low that makes them feel weak. Hence, the safest bet is to eat the candy within 5 to 10 minutes of starting activity. This span is too short for the body to respond. (Or, eat the candy more than 45 minutes before exercise to allow insulin levels to drop.)
Candy is better than nothing, but it's not premium fuel. It's better to eat a more wholesome snack like cereal, a banana or apple, yogurt, or pretzels and juice. The urge for a quick energy fix is a sign you've eaten too little food earlier in the day. To prevent cravings, eat a hearty breakfast and lunch.
When we travel to a 7 pm event, I often miss dinner. Any suggestions?
Traveling athletes commonly struggle to fuel properly. Sometimes they simply run out of
time. Or they get to the event and expect food to be provided--and find nothing left, or
nothing appealing or appropriate.
Your responsibility is to fuel yourself well throughout game day. That means, for example, getting up early enough to have a hearty pancake breakfast, eating a double serving of pasta or two big sandwiches at lunch, drinking water throughout the day for extra fluids, and making time for a pregame dinner. The key: Plan ahead.
The best pregame meals are carbohydrate-based: for example, spaghetti and tomato sauce (a little lean meat in the sauce is fine); or potatoes or rice, vegetables, and dinner rolls with a small serving of chicken or other protein-rich food (see "Timing Your Preactivity Meals," below). As with any pregame meal, choose foods that you know will settle comfortably and digest easily. Be sure to limit fried and high-fat foods like burgers, fried chicken, french fries, and nachos. These and similar fast foods take a long time to digest.
Too many athletes--most of whom know they should have a carbohydrate-rich pregame dinner--fail to plan meals into their schedule. If this sounds familiar, pack emergency food in your gym bag (see "Packable Snacks," below).
Snacks are better than nothing, but a good meal helps mentally, if not physically. Rather than regret improper eating, make time to eat well--perhaps even planning a mandatory team dinner--so you'll have energy to enhance your sports performance.
The rule of thumb for eating before exercise is to allow 4 hours for a big meal (about 1,200 calories), 2 hours for a light meal (about 600 calories), and an hour or less for a snack (about 300 calories). Sample carbohydrate-rich menus:
| Large Meal | Light Meal | Snack |
| 2 large bagels | 2 c spaghetti | 1 medium banana |
| 2 tbsp peanut butter | 1/2 c tomato sauce | 1 pkg instant oatmeal |
| 2 tbsp jam | 8 oz low-fat milk | 8 oz low-fat milk |
| 8 oz fruit yogurt | ||
| 16 oz orange juice |
So you won't go hungry if you're traveling to a night game, stash 1,000 calories of tried-and-true food in your gym bag. (Never try new foods before an important event.) You might even pack extra snacks for underfed teammates. On game day you can add perishable items such as yogurt, bagels, apples or other fresh fruit, or even a sandwich or two. Some possibilities:
Remember, you, your physician, and your nutritionist need to work together to discuss nutrition concerns. The above information is not intended as a substitute for appropriate medical treatment.
Ms Clark is director of Nutrition Services at SportsMedicine Brookline in the Boston area. She is a fellow of the American College of Sports Medicine, a fellow of the American Dietetic Association, and a member of its practice group, Sports, Cardiovascular, and Wellness Nutritionists (SCAN).
THE PHYSICIAN AND SPORTSMEDICINE - VOL 25 - NO. 10 - OCTOBER 97
A young, nondiabetic weight lifter became pale, diaphoretic, and markedly distressed while dining out; intuition and quick action may have saved his life. His case illustrates the perils of taking insulin for anabolic purposes. Physicians must learn to question patients about nutritional and pharmacologic supplement use to help them avoid the dangers not typically addressed in the popular fitness and alternative medicine literature.
My wife and I were waiting to be seated at a restaurant one evening when I noticed an imposing, muscular young man accompanied by a young woman also waiting for a table. He looked like a weight lifter or body builder, but he was pale and sweating profusely. His head drooped on his chest while the young woman tried to comfort him. After they were seated at a table near ours, I saw that the young man was still sweating and was whiter than ever. Soon he stood up, stumbled from his table, and left the restaurant, with his friend close behind.
I followed them outside and asked if I could help. When I talked to the young man, he just looked up, mumbled a few words, and held the wall for support. I reached down to take his pulse and felt cold, clammy skin; his heart was racing at more than 150 beats per minute.
His girlfriend said that he wasn't taking any medications, and she was unaware of his having any medical problems. She recalled, however, several recent episodes during which her boyfriend generally felt awful, sweated a lot, became dizzy and tired, and then recovered rapidly.
I asked the young man if he was having any pain or other symptoms that might clue me in to what was going on. He mumbled some words that I couldn't understand, and his eyes brimmed with tears. Clearly, he was in distress and deteriorating before my eyes.
I searched for explanations. Was this a simple case of the "flu" or was it something more unusual? Was he suffering the effects of a beta3 antagonist or of some thermogenetic product such as ephedrine or clenbuterol that many body builders use? (Muscle Media 2000 1996;51:123-126 and 1996;48:33-36) I thought about my personal and professional experience with body builders and about the lay literature on fitness and body building that I'd read. Then I recalled one of the latest fads being practiced by fitness buffs and serious athletes (Muscle Media 2000 1996;50:32-34) and believed it might be the key to this young man's condition.
I asked his friend to stay with him while I ran into the restaurant, grabbed 8 or 10 packets of sugar, and returned to the couple. With the help of the young woman, I poured the sugar into the young man's mouth (he was unable to do it himself). Within moments he was "cured." He had regained his color, was talking, feeling fine, and no longer sweating.
In talking with him, I learned that he was not diabetic and had no previous diagnosis of hypoglycemia or other medical problems. Yet he had been taking 50 units of regular insulin twice a day for about 2 months as a "growth stimulating supplement." He felt that insulin had given him the desired effect: muscle fullness and a modest 8- to 10-lb weight gain. Only one friend from the gym where he trained knew he was taking it. Ironically, he had quit just 4 days prior to the present incident, and only because he was afraid of the hypoglycemic episodes that his girlfriend had described. Unlike the other pharmaceutical aids that he was taking, such as testosterone cypionate and nandrolone decanoate, insulin and hypodermics for injection were easy to obtain--no questions asked--over the counter at any pharmacy, so he believed it was pure and safe.
Our patients have easy access to nutritional and, in some cases, pharmacologic supplements. If scientific medicine fails to meet our patients' needs, many will read the abundant literature touting the alleged benefits and will take such supplements. In fact, athletes have known for years about the anabolic properties of growth hormone and now have dug deeply enough into the endocrinology literature to find that insulin has both anabolic and anticatabolic actions (1). Whether insulin use actually causes increased muscle mass is unknown. Nonetheless, patients feel well-informed about the agents they are using.
This young man was typical. He knew that insulin promotes anabolism and increases protein, triglyceride, and very low density lipoprotein formation by the liver (2). He knew that insulin inhibits catabolism by acting to reverse catabolic events of the postabsorption state. He also knew that insulin increases protein synthesis in the muscles by increasing amino acid transport and stimulating ribosomal protein synthesis--the effect he was after. He knew that taking large amounts of insulin with plain sugar and other dietary supplements would promote storage of the nutrients (1). He even knew that he could die or have severe brain injury if he had a hypoglycemic attack and was unable to obtain simple carbohydrates (3).
Unfortunately, he was not aware of some other risks of insulin use (table 1). He didn't know that prolonged insulin use requires rotation of injection sites to prevent lipodystrophy or lipoatrophy. He mistakenly thought that he could recognize and treat an insulin attack before it was too late. He had no idea that combining excessive insulin use with rigorous exercise could result in more unexpected hypoglycemic attacks (3) even after quitting insulin use.
Table 1. Risks of Insulin Use (3)
Hypoglycemia
Effects from low blood-glucose concentration
Confusion
Unusual behavior
Neurologic deficits
Convulsions
Coma
Effects from epinephrine release
Vasoconstriction
Tachycardia
Profuse sweating
Fear and tension
Lipodystrophy and Lipoatrophy
Insulin Allergy
Insulin Resistance
Immunologic Response
Production of auto-antibodies against insulin
This young man's case is instructive because only one of his gym buddies knew about his insulin use. He didn't tell his girlfriend, parents, physician, or any other healthcare provider. Particularly poignant is the fact that no one asked about his substance use, and, as a result, his ignorance jeopardized his life.
Physicians and healthcare providers need to ask patients hard questions to gain the comprehensive knowledge that provides solid ground for patient care. We need to ask about all supplements that our patients, especially fitness enthusiasts, are using and, if necessary, ask them to bring in samples of each. Only then can we have a clear idea of the possible adverse effects and potential drug interactions.
An excellent approach to this issue is to call all supplements "pharmaceutical products," whether they come from the local health food store or are prescribed by a physician. This teaches patients to associate everything but food with medication and allows them to understand a physician's need to know about everything they are taking. Armed with such knowledge, physicians can at least help patients make informed decisions--and perhaps even save a life.
Dr Willey is a second year resident in family medicine at the Mayo Clinic in Scottsdale, Arizona. Address correspondence to J. Warren Willey II, DO, 13737 N 92nd St, Scottsdale, AZ 85260.
THE PHYSICIAN AND SPORTSMEDICINE - VOL 25 - NO. 8 - AUGUST 97
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Athletes used to think that if you wanted to bulk up your muscles, you just ate a lot of calories. Bodybuilders were notorious for eating several pounds of meat and up to a dozen raw egg yolks daily. Today we know not only that high-fat, high-protein diets are unhealthy, but that they don't promote lean tissue growth. The diet that will give you the greatest increase in lean body mass without causing a lot of fat gain is still high in calories--but the recommendations about where these calories should come from have changed a lot.
Building muscle requires tremendous energy, both to do the muscle-building exercise and to build the tissue itself. One study (Gail Butterfield, PhD, personal communication, January 1997) showed that each day strength-trained athletes needed about 20 calories per pound of body weight (44 calories [kcal] per kilogram [kg]) just to maintain their muscle mass--about 2,800 calories per day for a 140-pound person, 4,000 for a 200-pound person (table 1). Apparently even more--25 to 30 calories per pound of body weight (54 to 66 kcal/kg) per day--is required to build muscle (1,2).
| Table 1. Daily Calorie, Carbohydrate, Protein, and Fat
Intake for Strength Training: Sample Recommendations |
||||
| Body Weight (Pounds) | Calories per Day | Calories From Carbohydrate | Calories From Protein | Calories From Fat |
| 140 | 2,800 | 2,000 | 360-460 | 340-440 |
| 200 | 4,000 | 2,800 | 510-660 | 540-690 |
Carbohydrate. Getting enough calories is important, but so is getting the right kind of calories. Carbohydrate, stored in the body as glycogen, is the predominant energy source for muscle-building exercise. The harder and longer you work out, the more glycogen your muscles require. Once your muscles are depleted of glycogen, you have no more energy to continue your workout.
There are different ways to figure out your carbohydrate needs, but the bottom line is that with at least 500 to 600 grams of carbohydrate per day, your muscles will stay packed with glycogen. One method is to base your intake on 3.6 grams per pound of body weight (8 g/kg). At 4 calories per gram of carbohydrate, this means about 504 grams per day or about 2,000 carbohydrate calories for a 140-pound person, and 720 grams or 2,900 carbohydrate calories for a 200-pound person.
A second strategy for computing your carbohydrate needs is based on a percentage of total calories. When total energy intake is below 4,000 calories a day, getting 70% of those calories from carbohydrates will ensure the muscle power and endurance required to strength train. With a diet above 4,000 total calories a day, a lower percentage of calories can be obtained from carbohydrates, as long as you take in at least 500 to 600 grams of carbohydrate.
Protein. At this point you might be wondering, "What about protein?" Protein is the basic building material for muscle tissue, and strength trainers need to consume more than the rest of us. In the same study that looked at energy needs, researchers found that during weight lifting, those who ate enough calories required about 0.6 grams of protein per pound of body weight (1.2 to 1.3 g/kg) daily to maintain muscle mass. If the intensity of the exercise was increased to build muscle, the daily requirement went up to almost 0.7 grams per pound (1.5 g/kg).
Based on a wide review of scientific data (3), current daily protein recommendations for serious strength trainers are about 0.6 to 0.8 grams per pound (1.4 to 1.8 g/kg). This equals 90 to 115 grams of protein per day for the 140-pound strength trainer and, 128 to 164 grams for the 200-pounder.
Fat. Once you've determined your carbohydrate and protein needs, all the leftover calories--less than 30% of total calories--can come from fat. To keep your heart healthy, make sure that most of your fat calories are from unsaturated fats.
Next on the list of important nutrients is water. Good hydration is just as essential for strength training as it is for endurance training. Your body requires at least eight 8-ounce cups of caffeine-free, nonalcoholic fluids every day. You need to drink even more to replace fluids that are lost during exercise.
Make sure you go into your workouts well hydrated by drinking 2 cups of fluid 2 hours before exercise. During exercise, drink 4 to 8 ounces every 15 to 20 minutes. After exercise, replace any further fluid losses with 16 ounces of fluids.
Another approach is to weigh yourself before and after exercise: Any weight lost is fluid. Replace every pound lost with at least 16 ounces of fluid.
Most supplements that are supposed to help build muscle don't work. But some, such as creatine, fluid and electrolyte replacers, carbohydrate supplements, and liquid meal replacers may offer some benefits to strength training athletes.
Creatine. In the past several years, creatine has gained attention among athletes because it has the potential, when combined with a good diet and strength training program, to produce slightly more power during workouts. In addition, loading creatine into the muscles may help speed up muscle gain.
Meat is the best dietary source of creatine, and vegetarians generally have lower muscle creatine concentrations than meat-eaters. People at the lower end of the normal range for muscle creatine are the most likely to benefit from supplementation.
The usual dosage for creatine loading is 5 grams of creatine monohydrate four times per day for 5 days. A maintenance dose of 2 grams per day can follow. Taking more than the usual dosage of creatine offers no added benefit. Also, users should be aware that creatine and other popular supplements are subject to little government regulation, so there is no guarantee that they are pure.
Sports drinks. Fluid and electrolyte replacers are beneficial if exercise lasts longer than 1 hour. Carbohydrate supplements can be useful to help fit adequate carbohydrates into a busy day. Additionally, one study (4) indicated that by taking creatine with 17 ounces of liquid carbohydrate supplement, muscle creatine concentrations can be boosted by up to 60%.
Consuming a meal-replacement beverage just after muscle-building exercise may be a convenient way to help stimulate muscle growth. Protein and carbohydrates trigger the release of insulin and growth hormone, which are integrally involved in muscle growth. Meal replacement beverages are also great for adding well-balanced calories when you just don't have the time to eat a meal.
Even though supplement purveyors promise easy results, gaining muscle takes determination, a good diet, and lots of sweat. Stick to it, and you'll be pleased with your results.
Remember, you, your physician, and your nutritionist need to work together to discuss nutrition concerns. The above information is not intended as a substitute for appropriate medical treatment.
Dr Kleiner is a private nutrition consultant to athletes in the Seattle area. She is a member of the American College of Sports Medicine; a member of the American Dietetic Association and its practice group, Sports and Cardiovascular Nutritionists (SCAN); and a fellow of the American College of Nutrition.