Essentials of Nutrition for Sports

with a two-hour high-intensity ride: 3,000 total calories—2,000 calories for the activity and 1,000 calories for basal metabolism. If you do this every day of the week, and if you ingest just 2,500 calories, the deficit of 500 calories will contribute to an average weight loss of one pound a week. If you have only two hours, you will burn fewer calories with low-intensity work than with high-intensity work. Moreover, with a caloric surplus of 500, you will gain

an average of a pound a week.

Calories Used

65% Max HR 2 Hours

65% Max HR 4 Hours

85% Max HR 2 Hours

Daily basal: Fat

1,000

1,000

1,000

Exercise

1,000

2,000

2,000

Glycogen

150

300

1,200

Fat

850

1,700

800

Daily total: Fat

1,850

2,700

1,800

Daily total: Glycogen and fat

2,000

3,000

3,000

Table 3. Daily basal and exercise calories used during exercise of selected duration and intensity. Max HR, maximum heart rate.

A 2,500-calorie diet that is 65%

carbohydrate will provide 1,625

calories toward glycogen replacement. A 40% carbohydrate diet will provide only 1,000 calories of carbohydrate.

If you eat a high-carbohydrate diet, you will be able to better

replace your glycogen, and you will be able to train day after day. If you do not, your glycogen tank will not be filled. After a few days you won’t be able to train at as high an intensity level, and you’ll run out of high-performance energy—glycogen. You will have to train more slowly and longer to lose as much fat.

The moral is this: if your time is limited, within the limits of

your overall training program, ride hard and eat a high-carbohydrate diet.

Carbohydrate Chemistry^ Carbohydrates are simple sugars; complex sugars, or starches;

and indigestible sugars, or fiber.

Simple Sugars

Simple sugars are categorized as single- or double-molecule

sugars.

Single-molecule

sugars include glucose, fructose, and galactose.

Double-molecule

sugars include sucrose (table sugar—a glucose

and a fructose molecule), lactose (milk sugar—a glucose and a galactose molecule), and maltose (malt sugar—two glucose molecules).

Refined

sugars are processed sugars

devoid of other nutrients.

Natural

simple sugars, found in fruits, juices, milk, and

vegetables are associated with vitamins and minerals.

Simple sugars are the building blocks of complex sugars, or

starches.

Foods and drinks with a lot of simple sugars or simple

carbohydrates are often sweet. They include candies, fruit, and nondiet soft drinks. Simple sugars us

ually come with few vitamins or

minerals and are therefore often referred to as “empty calories.”

Complex Sugars—Starches

When simple sugars form long chains of carbohydrate, they are

called “complex.” Complex carbohydrates, or starches, are often associated with other nutrients. Foods consisting primarily of complex carbohydrate are pasta, breads, potatoes, and grains. Ingested complex carbohydrate is digested (broken down) into simple sugars before being abso

rbed into the bloodstream.

Nutrition for Sports, Essentials of 45