You know that carbo-loading preps your body for a big effort by topping off glycogen stores in your muscles and liver. But not all pasta parties are equal. Some carbs (like white pasta) hit your system hard, giving you a quick boost but dropping off abruptly, while others (like whole-grain pasta) are processed slowly, supplying sustained energy. This difference in the blood-sugar spike is called the glycemic index (GI) or glycemic load (GL). (You'll see both terms in the marketplace.) High-glycemic foods are particularly helpful for training and recovery eating, when you need to replenish glycogen quickly. For routine meals and snacks, however, round out your diet with foods lower on the glycemic scale. The most important thing is simply to remember that athletes need a mix of low-, moderate-, and high-glycemic carbs in their daily diet. Use the following guide.

Glycemic Index: Low = less than 55; moderate = 55–70; high = more than 70
Glycemic Load: Low = less than 10; moderate = 11–19; high = more than 20

Here are GL figures for some common foods. Get more at glycemicindex.com.

HIGH
Baked potato
Serving size: 7.1 oz; Total carbs: 29 g; GL: 27.3

Spaghetti (white)
Serving size: 6.4 oz; Total carbs: 44.3 g; GL: 25.7

Bagel (white)
Serving size: 2.5 oz; Total carbs: 35.5 g; GL: 25.6

Pancakes
Serving size: 2.8 oz; Total carbs: 32.5 g; GL: 21.8

MODERATE
Muesli
Serving size: 1.8 oz; Total carbs: 30.2 g; GL: 18

Spaghetti (whole-grain)
Serving size: 6.4 oz; Total carbs: 44.3 g; GL: 14.2

Sweet potato
Serving size: 5.3 oz; Total carbs: 26 g; GL: 12.5

Banana
Serving size: 4.2 oz; Total carbs: 23.9 g; GL: 12.2

Orange juice
Serving size: 9.3 oz; Total carbs: 21.1 g; GL: 12

LOW
Apple
Serving size: 4.2 oz; Total carbs: 14.6 g; GL: 5.9

Lentils
Serving size: 5.3 oz; Total carbs: 14.9 g; GL: 4.2