Eating for Exercise

Are you just beginning an exercise program, determined to get into better shape? Or are you a serious recreational athlete competing in races or other athletic events? Whatever your activity status, your food and beverage choices can enhance - or impede - your progress and performance. Eating enough calories, carbohydrates, protein, and fat, and getting the right amount of fluids in balance with a good exercise program will produce high energy, improved endurance, increased muscle strength, and a healthy weight.

Calories
Carbohydrates
Protein
Fats
Fluids

Calories | top

Your calorie needs during exercise are determined by your height, weight, gender, age, body composition, level of fitness, as well as the duration and intensity of your workouts.

Use the calorie calculator at right to estimate your energy expenditure in one day. Enter your gender, weight in pounds, and level of physical activity in the spaces provided. See below for examples of physical activity levels.

Sedentary: You sit down most of the day or drive/ride whenever possible; includes playing a musical instrument or video game, standing still, studying and working on the computer.

Light activity: You move around some of the time, as a teacher might during working hours; includes house cleaning, leisure walking, and games such as table tennis.

Moderate activity: You engage in some intentional exercise, such as an hour of fast walking four or five times a week, or your daily schedule calls for some physical work such as carrying a load for distances, recreational bicycling, skiing, tennis, dancing, or active gardening such as hoeing and weeding.

Heavy activity: Your daily activities include much physical labor (more than one hour per day) such as fast jogging or running, soccer, basketball, hauling heavy loads uphill, or working as a carpenter, roofer or engaging in other forms of sustained manual labor.

Exceptional activity: The exceptional category is reserved for those few who spend many hours a day in intense physical training, such as professional or collegiate athletes during their training seasons.

Carbohydrates | top

Carbohydrates (or 'carbs') are the fuel of choice for muscles. In muscle, carbs are stored as glycogen where they can be used during exercise to provide energy and keep blood sugar levels even. Carbohydrates are important for endurance athletes as well as body builders and for anyone who trains hard day after day.

Whole grains (breads, cereals etc.), vegetables and fruits are the best sources of carbohydrates because they are loaded with vitamins, minerals, antioxidants, and fiber. Eating these foods throughout the day will keep you well fueled for all your activities, especially your physical activity. For moderate activity (4-5 times weekly for up to one hour), follow the food guide pyramid for appropriate nutrient balance. If you are training for longer events the pyramid is still your best guide, but you can maximize your carbohydrate use by 1) eating carbs within 30 minutes after exercise to enhance glycogen storage and 2) careful timing and selection of certain types of high carb foods (see Eating for Endurance).

Eating for Endurance
Controlling the “glycemic load” of meals and snacks is gaining popularity in the field of sports nutrition as a way to maximize energy levels before, during and after endurance events. The basic idea is that foods with a high glycemic load are quickly digested and therefore, will boost blood sugar within minutes. These foods would be best used during or after exercise when you need to refuel in a hurry. Low glycemic load foods are slower to digest and boost blood sugar, so they are better used before exercise for more sustained energy.

For more information and a list of high and low glycemic foods see:
Sports Science News: Using Glycemic Index to Improve Athletic Performance
WebMD - Whole Foods Best for Workouts
The Glycemic Index

Some initial research results show there may be a benefit to this practice, but be aware that the science is still young and data are still preliminary. Just remember, if you want to try controlling glycemic load, be sure to experiment while training, not before or during an event!

What About Carbohydrate Loading?

Storing as much glycogen as possible in muscle can help an endurance athlete go longer and with more intensity. The only way to increase glycogen storage is to train muscles through exercise; simply eating more carbohydrates won't help. For example an untrained muscle can store about 13 grams of glycogen per 100 grams of muscle, while a trained muscle can store up to 32 grams of glycogen. It is possible to store up to 35-40 grams of glycogen in 100 grams of muscle through “carbohydrate loading.” For an endurance event that will last for more than 90 minutes follow these steps to maximize muscle glycogen:

Throughout training, consume a diet with 60-70% of calories from carbs
Gradually reduce your training for 7-10 days prior – this rests your muscles and allows them to become saturated with carbs.
Consume at least 70% of calories from carbs 3-4 days before your event (4-5 g carbs/lb body weight)

For more information:
NYC Marathon: Monthly Training Tips - October Training Tip: Carbohydrate Loading
Australian Sports Commission - Web Archive Copy: Hot topics - Carbohydrate Loading

Protein | top

Protein is important in exercise for building and repairing muscle, but it is also needed for a healthy immune system, producing hormones and building red blood cells. Protein can do all of these things as long as you eat enough calories to meet your energy needs. If you restrict calories too much, protein is burned for energy when carbohydrates are scarce. On the other hand, if you overeat on any of the major nutrients, including protein, it will be stored as fat. Eating the right amount and balance of foods will ensure the best results for any exercise program.

How much protein do I need?
For a sedentary adult, the protein need is 0.4 grams per pound of body weight. These are the needs for active people in grams of protein per pound of body weight:

Adult recreational exerciser 0.5-0.75 gm
Adult competitive athlete 0.6-0.9
Growing teenage athlete 0.8-0.9
Adult building muscle mass 0.7-0.9
Athlete restricting calories 0.8-0.9

These amounts are easily met with food; typically, protein supplements are not needed to build muscle. Muscle can only be built with appropriate training – extra protein in the diet won't add an ounce of muscle if there is no training! In fact, any amount consumed in excess of 0.9 gram per pound will not be used by your body.

Food	Serving Size	Grams of Protein
Egg	1 large	6
1% Milk	1 cup	8
Cottage Cheese	1/2 cup	15
Yogurt	1 cup	11
Fish	4 oz cooked	27
Hamburger	4 oz broiled	30
Chicken breast	4 oz	35
Tuna	4 oz	27
Peanut butter	2 T	9
Kidney beans	1/2 cup cooked	7
Tofu	3.5 oz	11
Almonds	12 nuts	3
Hummus	1/2 cup	6
Grains and Vegetables	1/2 cup	2-3

The Physician and Sportsmedicine: The Power of Protein
WebMD - Will Eating More Protein Help Your Body Gain Muscle Faster?
WebMD - Post-Workout Foods to Build Muscle

Fats | top

A heart healthy diet for active people consists of 20 to 30% of calories coming from fat. If you eat too much fat you can increase your risk for heart disease, whereas too little fat can actually inhibit athletic performance. It is also important to include more plant fats (high in monounsaturated and polyunsaturated fats) such as nuts, seeds, olives, olive oil, canola oil, avocadoes, and peanut butter, and fewer animal fats (higher in saturated fats) such as whole milk, cheese, ice cream, high fat beef and pork. Limiting trans fatty acids (hydrogenated oils) and fried foods can also reduce your risk for heart disease.

Calorie Needs per Day	Grams Fat in Diet
Calorie Needs per Day	20%	25%	30%
1800	40	50	60
2000	45	55	65
2400	53	67	80
2600	58	72	87

Fluids | top

Why are fluids so important for active people? Water and other fluids are important for everyone, but when you're active, enough fluids are crucial for the extra work you're doing, becuase they help to:

Transport glucose in the blood to working muscles and carry away metabolicby-products
Eliminate metabolic waste products in urine
Regulate body temperature through sweating
Cushion joints

A general rule of getting enough fluids is to drink 1 liter of fluids for every 1000 calories you expend. Be sure you drink enough--or more--to quench your thirst. You can also check your urine color to tell if you are well-hydrated or not. If your urine is dark and volume is small – you need to consume more fluids. Water, juices, and sports drinks are your choices for fluid. Beer and other alcoholic beverages have a dehydrating effect, so they are not appropriate fluids for exercising individuals.

Dehydration can lead to heat exhaustion and symptoms include: increased body temperature, fatigue, headache, chills, rapid pulse, clammy skin, nausea, and dizziness. Heat stroke can occur when there is more than 10% dehydration – symptoms include hallucinations, no sweat or urine and an unsteady walk. Both heat exhaustion and heat stroke need to be treated immediately.

The American College of Sports Medicine's recommendations for fluid consumption before, during and after exercise and athletic competition including the following:

Consume a nutritionally balanced diet and drink adequate fluids during the 24 hours before an event.
Drink about 2 cups of fluid about 2 hours before exercise.
During strenuous exercise drink at regular intervals to try to replace the water lost through sweating, or, drink as much as can be tolerated.
During and after exercise lasting more than one hour a sports drink may be appropriate; water is best for less than one hour. Rehydrating after exercise is also important to recovery.

For more information on these recommendations see:
Exercise and Fluid Replacement
Gatorade Sports Science Institute: Educational Tools
Iowa Beef Industry Council - Sports Nutrition