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Eat to swim ... bike ... run ....

Eat To Swim...Bike...Run...

It's summer, and record numbers of Americans are getting up off the couch and into their sneakers.

But many nouveau exercise enthusiasts are perplexed by conflicting and confusing advice about how to "eat to win." When should athletes eat most of their calories? Do amino acids help build muscle? What kind of diet and exercise program will help them lose the most pounds in the least amount of time?

To answer these and other questions, NAH turned to Nancy Clark, a Massachusetts-based nutritionist who specializes in sports nutrition. Clark has counseled clients ranging from high school swim clubs to the Boston Celtics. Turn to page four for an interview with the "athlete's nutritionist."

"Everybody needs to eat a sports diet, whether they're a marathon runner or a couch potato," asserts Nancy Clark. A nutritionist at SportsMedicine-Brookline, one of the largest sports medicine clinics in the country, Clark counsels individuals and groups of health professionals, coaches, teams, and parents.

She also publishes a one-page newsletter called "The Athlete's Kitchen," available free to reporters, teachers, or others who reprint the information. Clark spoke with NAH from her office in Brookline, Massachusetts.

NAH: Do very high doses of vitamins and minerals affect athletic performance?

NC: I doubt that high doses really hinder performance, but they don't enhance performance either. Most hungry athletes get powerhouse doses of vitamins and minerals from their lumber-jack portions of food. If they drink a quart of orange juice after a tennis match, for example, then they're getting all the vitamin C they need. If they chow down three baked potatoes after a workout, they're getting all the potassium they need.

NAH: Do many athletes take vitamin supplements?

NC: A Runner's World survey showed that 75 percent of the magazine's subscribers took supplements. I did a survey of the top women runners in the country, and 91 percent of these women took vitamins. The majority in both surveys are taking a multivitamin, and some also take iron. The women are more likely to take B vitamins and calcium as well.

If athletes want to take supplements, that's their choice. My job as a nutritionist is to teach people how to eat well. I just remind them that most vitamin pills supply maybe 8 or 10 of the more than 40 nutrients that you need.

NAH: In your newsletter, you talk about "sports foods." What are they?

NC: Foods that are nutrient dense [those that have lots of vitamins and minerals per calorie], such as lowfat milk, lowfat yogurt, broccoli, tomatoes, oranges, strawberries, lean beef, chicken, turkey, fish, bran cereals, popcorn as an alternative to chips, and a single cheese pizza with vegetables, on a whole wheat crust if it's available.

NAH: Are certain diets better for certain sports?

NC: Everybody needs a sports diet to promote heart health. The diet should be high in carbohydrates and low in fat.

Beyond that general advice, an endurance athlete, such as a marathon runner, needs to consume more calories than a gymnast, who moves less. It's best to get those extra calories from carbohydrate-rich foods, because carbohydrates get stored in muscles as glycogen. When you're exercising aerobically, you're using glycogen for fuel.

NAH: What quantity of carbohydrates should people eat every day?

NC: Sixty percent of your calories should come from carbohydrates. But most athletes--most Americans--have no concept of what that is. To give them an idea, I tell them that only one-third of the plate should be covered with protein, and two-thirds with carbohydrates. For example, I have people eating two potatoes instead of two pieces of chicken. I also tell them to knock off the fats.

NAH: Is it important to eat breakfast?

NC: Breakfast is the meal of champions. If you exercise before breakfast, you need food to refuel your muscles. The first two to four hours after a workout is when your body is most efficient at replacing depleted glycogen stores.

On the other hand, if you exercise in the afternoon or evening, you'll need that food to fuel a high-energy workout. If you're running on low blood sugar, you're not going to get very far.

NAH: Does drinking one to two glasses of wine or beer a day have a measurable effect on athletic performance?

NC: Since alcohol does not get stored as muscle glycogen, it's not a good source of energy. Most serious athletes don't drink the day before a competition.

Alcohol also has a dehydrating effect. If you've been drinking, it's a good idea to monitor your hydration level by checking the color of your urine. During the day, urine should be a clear color and excreted in significant amounts. If you don't go to the bathroom frequently, and your urine is a dark color, you should be drinking more water.

NAH: Does caffeine enhance endurance?

NC: Caffeine was once thought to cause your body to burn proportionately more fat. Theoretically, that would conserve glycogen, which your body has in shorter supply than fat. But recent research is showing that if you're properly fit, carbohydrate-loaded, and ready to compete, caffeine doesn't boost performance.

NAH: How does a high-protein diet affect athletic performance?

NC: A person who is eating a high-protein diet is usually eating a low-carbohydrate diet, which means that the muscles will be sub-optimally fueled. Protein breaks down into urea, which increases the need to urinate. In addition to being inconvenient, this increases the risk of dehydration. High-protein diets also tend to be high in fat, which is a poor choice for heart health.

Since excess protein does not get stored in the body as muscle, there is no "competitive advantagec to eating a high-protein diet.

NAH: Is it true that sports such as weightlifting require more protein than the Recommended Dietary Allowance?

NC: Yes. The current RDA for protein is 0.8 grams per kilo of body weight [1.8 grams per pound]. But research indicates that for an active person, 1.4 grams per kilo may actually be more appropriate. I generally recommend 1.5 [3.3 grams per pound], because it's an easier number to calculate.

That works out to be about 15 percent of total calories from protein. But if someone's on a very low-calorie diet--for example, eating only 1,000 calories a day--then 15 percent equals only 150 protein calories. That may be inadequate. A 20-percent-protein diet might be better.

But most Americans eat more protein than they need. Chances are, the higher recommended protein intake for athletes just means that there is less excess in what they're already consuming.

NAH: Does anybody get too little protein?

NC: Yes. I am concerned about certain athletes who don't call themselves vegetarians--they just call themselves "non-meat-eaters." These are the folks that take great pride in eating a high-carbohydrate, low-fat diet. Unfortunately, it's also very low in protein.

The classic example is a woman I spoke with who told me she typically ate a big bowl of fruit for breakfast, a humongous salad at lunch, and rice and stir-fried vegetables for dinner. The problem is, this diet provides her with inadequate amounts of protein, and not enough iron, calcium, and riboflavin.

People who are vegetarians make an effort to eat plant protein -- peanut butter, garbanzos, beans. But there's a breed of non-vegetarian athletes that are so carbohydrate-conscious, they forget that some protein is an important part of their diet.

NAH: Do amino acid supplements build muscle?

NC: Muscles need all the essential amino acids--not just one--to create protein. It's sort of like playing Scrabble with only the "E's"--you can't spell any words. Also, amino acid pills are incredibly expensive. If you want the amino acid, arginine, for example, you could eat a can of tuna fish and get double the amount in a supplement.

NAH: Let's say someone wants to lose body fat. What kind of dietary and exercise regimen should he or she follow?

NC: I would advise the person to participate in aerobic exercise, and to pay attention not only to what they eat, but when. Research indicates that during the day, you are more likely to burn off calories than to store them up.

Basic physiology indicates that if you're dieting at breakfast and lunch, and trying to exercise also, you may get so hungry that you won't have the energy to exercise. Even worse, if you don't exercise, you're more likely to lose control of your diet, because you've gotten too hungry. I encourage my clients to eat two-thirds of their calories by 4 p.m.

NAH: Do people ever express discouragement to you about the surprisingly small number of calories that are burned during exercise?

NC: Yes--exercise doesn'tt burn as many calories as many people think it does. But it has other important health benefits. Regular aerobic exercise reduces the risk of diabetes, heart disease, high blood pressure, and possibly cancer. It also relieves stress.

NAH: How long should it take someone to lose 10 pounds?

NC: I recommend a weight loss of one to two pounds a week for a woman, and two to three pounds a week for a guy. But it varies.

Some people I counsel exercise a lot, but just don't lose weight. Their bodies don't want them to. Mother Nature didn't design everybody to be thin. In fact, you can feel overweight but be very healthy and at a normal weight for your body. There's a lot of re-thinking we need to do about body image. Right now, many women are just punishing themselves.

NAH: If you're intentionally restricting your calories to about 1,200 a day and exercising, should you be taking a multivitamin and mineral supplement to cover your bases?

NC: Under those conditions, taking a multivitamin with iron and zinc would be a fine idea. Also, it's important to eat quality calories. Don't waste them on ice cream.

NAH: How do female athletes differ in their nutritional needs from male athletes?

NC: Women tend to eat fewer calories, and so they are more likely to develop nutritional deficiencies, particularly if they're diet-conscious and eating poorly. They also have a greater need for iron and calcium.

In general, women should eat more nutrient-dense foods. A guy can eat a couple of Twinkies and it doesn't matter much -- what's two Twinkies amidst 5,000 calories? But a dieting woman who eats 280 calaries worth of Twinkies out of a total of 1,500 for the day risks missing out on important nutrients.

NAH: Do female athletes need more iron and calcium than sedentary women?

NC: Actually, sedentary women may need more calcium, because exercise helps to promote bone density. A female athlete might, however, need a little more iron--particularly if she's a runner--because runners have a higher risk of becoming anemic.

Some female athletes stop menstruating. In this case, they would need less iron. But they would have a much greater need for calcium, because their estrogen levels are lower. This increases their risk of osteoporosis. Women who don't menstruate have a 4-1/2 times greater risk of developing fractures.

NAH: Can a combination of diet and exercise alleviate premenstrual syndrome (PMS)?

NC: Most women don't know that their metabolic rates increase 300 to 500 calories a day, one to two weeks prior to menstruation. Many women feel they're getting bloated, so they try to diet at a time when they need more, not fewer calories. They may get irritable because they're hungry.

I recommend that women who suffer from PMS give themselves permission to have a bigger breakfast and lunch. They'll probably feel better, and they'll have the energy to exercise.

NAH: Is water the best fluid to consume during exercise?

NC: Everyone used to say, "Just drink water during exercise." Now research is showing that it's fine to have some sugar in that water. And taking in some calories during endurance exercise can enhance your performance.

New research shows that the body can absorb as much as 60 to 70 grams of glucose [15 to 18 teaspoons of sugar] in an hour. That's 240 calories an hour.

A 2-1/2 percent solution [of sugar in water] was originally recommended. Now they say that 7 to 10 percent solutions--the same as a soft drink -- don't cause dehydration or slow gastric emptying.

If you're running a marathon or competing in a 100-mile bike race, taking in calories during exercise will be to your advantage. But if you're just going out for a five-mile run, your body has plenty of stored glycogen to fuel the exercise.

NAH: For people who do "drink on the run," what do you recommend?

NC: Sports drinks that contain glucose polymers [chains of sugars] have the advantage of emptying the stomach faster than regular sugars. [The sooner food leaves the stomach, the sooner it reaches muscles.] Some people like them. Some don't. You have to experiment.

Of course, you don't have to have either a sports drink or a soft drink. Any sort of carbohydrate can do the trick. You could have some apple juice. Or you could eat a banana and drink water. You need to have adequate fluid along with some calories.

NAH: Do you need to consume Gatorage-type drinks to replace electrolytes, such as sodium and potassium, that are lost in sweat?

NC: No, because during exercise, you lose proportionately more water than you do electrolytes, so that their concentration actually increases in your body. Your first need is fluid. After exercise, you can replace lost electrolytes when you eat food. Fruit juices, for example, are high in potassium. A large glass of orange juice replaces all the potassium you might have lost during a marathon.

NAH: How much fluid should you drink after exercising?

NC: Weigh yourself before and after you work out. For every pound you lose, you'll need to replace one pint of fluid. Thirst is not always adequate to tell you if you've had enough to drink.

NAH: How does someone know if they're becoming a compulsive athlete?

Nc: It's when your life isn't working for you. Exercise should be fun; training should be enjoyable. But if you're out there pounding yourself, dragging yourself out of bed in the morning to go run for 10 miles when you need lots of coffee to get you moving, you'd be better off in bed than out there.

There should be an element of flexibility in your exercise. You shouldn't have too many rules and regulations, such as "I'm going to run eight miles every day." Some people become so compulsive that they'll keep exercising even when they're sick or injured.

NAH: Does eating just before exercising provide quick energy?

NC: If you're starved at 4 p.m. and you're meeting a friend to go running at 5, nibbling on carbohydrates such as a few crackers or a banana will take the edge off your appetite and boost your energy. But don't make this a habit. Make a promise to yourself that tomorrow you'll eat a bigger breakfast and lunch, which will give you sustained energy through the afternoon and into the evening.

NAH: Can exercise relieve constipation?

NC: Yes. Regular exercise, fluids, and fiber--that's what I recoomend.

NAH: About 50 percent of Americans are sedentary. What would you recommend for people who have a hard time getting themselves to exercise?

NC: I'd ask them what they like to do or can do. Most people like to walk. At first, maybe they could walk around the block, and then the next week they could do two blocks. The third week, they could try alternating walking for two minutes, then jogging for one.

The idea is to get into exercising gradually enough to enjoy it. It's not medicine, if's fun. Any exercise is better than no exercise.
COPYRIGHT 1988 Center for Science in the Public Interest
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1988, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

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Publication:Nutrition Action Healthletter
Article Type:Interview
Date:Jun 1, 1988
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