How to benefit from monitoring food’s Glycemic Indexes in order to support your fitness and sports workouts

How to benefit from monitoring food’s Glycemic Indexes in order to support your fitness and sports workouts

Introduction and energy synthesis

Many people aware of diabetic’s limitations and the need for diabetic- people to control the level of sugar (Glucose) in the blood. Actually, such monitoring can be important to many, regardless of diabetics. Monitoring blood sugar level is important to anyone who tries to optimize eating for exercising and nutrition results. Before diving into the details of glycemic terms and conditioning, let’s first understand the basics of sugars, energy, and food to energy transformation in our bodies. Then, we can discuss what the Glycemic index is and how to benefit from monitoring it.

All parts of the body (muscles, brain, heart, and liver) need to have energy in order to work. This energy comes from the food we eat. Our bodies digest the food we eat by mixing it with fluids (acids and enzymes) in the stomach. When the stomach digests food, the carbohydrate (sugars and starches) in the food breaks down into another type of sugar, called glucose.

The role of insulin

The stomach and small intestines absorb the glucose and then release it into the bloodstream. Then, once in the bloodstream, glucose can be used immediately for energy or it will be stored for later use.

However, our bodies need insulin in order to use or store glucose for energy. Without insulin, glucose stays in the bloodstream, keeping blood sugar levels high.

Producing Insulin is triggered by the level of glucose in our blood. Then, it is released into the bloodstream and signals the body’s cells to receive the glucose from the blood.

Once received, the cells use the glucose to produce immediate energy or to store the glucose for later use as glycogen.

If we consume too much glucose and, exceeding the capacity of storing glycogen, then the body will store the energy as fat.

How to benefit from monitoring food’s Glycemic Indexes in order to support your fitness and sports workouts

Glycemic index and Glycemic load

It is important, regardless of fitness goals to control blood glucose levels. High sugar levels for long periods of time increases the risk of for diabetes complications such as kidney disease, nerve damage, retinal disease, heart disease, and even stroke.

People with healthy glucose management (not suffering from Diabetes) have the possibility of the body to keep glucose levels within the normal range, using the Insulin hormone.

There are two terms related to the sugar levels control you might be aware of and are important for this purpose of optimizing food for fitness: Glycemic Index and Glycemic Load.

Glycemic Index (GI)

GI indicates the rise time of the blood sugar levels after a particular food is consumed. This index is defined by the available carbohydrate in a food, which raises a person’s blood glucose level, relative to the consumption of pure glucose (which has a glycemic index of 100).

The actual Glycemic index of a food can change based on several parameters and not only the ratio of the carbohydrates inside it. These include the way the food is being prepared and stored.

Glycemic Load (GL)

GL not only takes into account the Glycemic Index itself but also the actual amount of carbohydrates consumed in a portion of food. The GL indicates better the level itself (and not just how fast) of the glucose in a person’s blood.

The glycemic load is calculated by multiplying the glycemic index value by the number of grams of carbohydrate, then dividing by 100.

The amount of carbohydrates to consume depends on a person’s age, activity level, sex, health status, and weight.

Lower Glycemic indexes mean less impact on our blood sugar levels, higher indexes mean higher impact on our blood sugar levels and this is what we would like to monitor and control.

Usually, Glycemic index tables are divided to high GI (70 or more), medium GI (56-69), and low GI (55 and below), as can be seen in the table below.

It is easier to control weight and decrease the risk of related diseases when controlling and maintaining the blood sugar levels low.

Use of Glycemix values when exercising supporting your fitness goals

During an intense workout, your body consumes stored energy (available glucose and glycogen) very quickly.

This is why intense runners, HIIT trainers, and other high-intensity sports activities, would like to have fast loading carbs available for the workout or competition hence one will need to plan the daily nutrition for optimized results.

It is not practical to plan all meals around the GI of foods. When the desire is to increase muscle glycogen, especially after intense exercise, it may be more practical to handle the following:

  • provide 50–100 g (200–400 kilocalories) of high GI carbohydrate to athletes immediately after glycogen-depleting exercise
  • Encourage athletes to eat high-carbohydrate foods that are packed with vitamins and fiber, especially whole grains, fruits, and vegetables. High GI foods and high-carbohydrate sport nutrition products can also help improve glycogen replacement and are especially helpful during times of intense training or competition

Low GI/GL food consumption for sports

Conversely, consuming moderate and low GI foods may also play a role in sports because these foods slowly allow glucose to enter the bloodstream. For example, it has been shown that moderate GI foods fed before endurance exercise actually help prevent the fall in blood glucose observed during 90 minutes of exercise compared to higher GI foods (Kirwan, O’Gorman & Evans 1998). Thus, foods with lower GI scores might work in the following situations:

  • Athletes who want to minimize changes in blood glucose should select more medium to low GI types of foods (beans, legumes, whole grains, fruits or vegetables). Moderate and low GI foods are good choices for mealtimes when rapid carbohydrate replacement is not a critical issue.
  • Athletes who are doing endurance exercise may want to consume a moderate to low GI meal before exercise to promote sustained carbohydrate availability during exercise.

One needs to keep in mind that of course Glycemic index values are not the whole picture and we need to have a variety of foods, having all required for our diet goals, whether its weightlifting progress or weight-loss. Good balance of Protein, fat, carbohydrates and fruits and vegetables. All are required.

But managing the glycemic index values of the food we eat is beneficial especially when trying to boost your energy before a big game or workout. Eating the right carbohydrates before and during exercise helps maintain blood sugar levels, prevents fatigue and improves performance. Eating the right carbohydrates after a workout or game can result in greater glycogen replacement and improved muscle synthesis.

Nutrition tips for Glycemic management

Here are some additional guidelines to follow in order to manage right the glycemic values and having the right carbs for the right time to support your fitness goals

  • Several hours before you exercise, eat low to medium glycemic foods that are slow to digest to keep you fueled during exercise. Good bets include oatmeal with fruit, baked sweet potatoes and oat bran cereal with milk.
  • Thirty minutes before exercise, eat or drink high glycemic food such as fruit juice, cornflakes with milk, or a sports drink.
  • During intense workouts, eat or drink a high glycemic food such as raisins, pretzels, gel or a sports drink for rapid digestion and increased blood sugar.
  • Immediately after exercise, eat high glycemic carbs combined with protein for faster recovery and increased muscle synthesis. This may include Greek yogurt with a banana, raisins with string cheese and low-fat chocolate milk. It is important to fuel our muscles post-exercise not too late as we want to give muscles the required energy for proper functioning and not having empty storage that can harm us.
  • During the rest of the day and during meals, eat low to moderate glycemic carbohydrates. Some good choices include rice, hummus, 9-grain whole grain bread, beans, and pears.

Summary and practical recommendations

 The Glycemic Index has already been incorporated by some educators into dietary advice for athletes. However, some caution is needed in making recommendations:

  1. The Glycemic Index was not intended to provide a complete ranking of the virtues of carbohydrate-rich foods. Remember other characteristics of food that are important – such as the total nutritional content of a food, cost, taste, practicality, and gastric comfort. Choose meals and snacks according to the goals and needs of each situation.
  2. Be aware that some individuals or situations may benefit from the choice of a low GI pre-event meal. These include athletes who show an exaggerated and detrimental response to the intake of carbohydrate-rich foods prior to exercise or events where it isn’t practical to consume significant amounts of carbohydrate during the session. In these cases, a low GI carbohydrate-rich meal may enhance performance by better maintaining carbohydrate availability throughout the event.
  3. Carbohydrate intake during exercise minimizes the metabolic impact of the pre-exercise meal. Therefore, feel free to choose a pre-event menu from carbohydrate foods and drinks that are practical, enjoyable and based on previous successful experiences.
  4. In endurance sports or activities, consume carbohydrate regularly throughout the event, aiming for a target of 30-60 grams per hour.

Choose carbohydrate choices of moderate to high GI (most sports drinks and popular exercise snacks fit this description). Practice in training to fine-tune your tactics.

  1. Enhance post-exercise refueling or carbohydrate loading by consuming adequate amounts of carbohydrate (1 g per kg body weight immediately after exercise, and a total of 7-10 g carbohydrate per kg body weight per day). While low GI carbohydrate-rich foods can contribute to total carbohydrate intake, it makes sense to focus on carbohydrate-rich foods and drinks with a moderate to high GI.

You may want to see calories BMI/BMR calculators and tables which help you build the right image of your nutrition.

Table of Glycemic Index and Glycemic Load values:

Foods that contain few or no carbohydrates, do not have GI value. The list of such food includes meat, fish, nuts, oils, and herbs and spices.

Foods that have low GI value are whole grains products, fiber-rich products like oats or muesli, legumes, vegetables and most of the fruits.

Food GI Serving Size (g) GL
Honey 87 1 Tbs 3
Jelly Beans 78 1 oz 22
Snickers Bar 68 60g (1/2 bar) 23
Table Sugar 68 2 Tsp 7
Strawberry Jam 51 2 Tbs 10.1
Peanut M&Ms 33 30 g (1 oz) 5.6
Dove Dark Chocolate Bar 23 37g (1 oz) 4.4
Corn Bread 110 60g (1 piece) 30.8
French Bread 95 64g (1 slice) 29.5
Corn Flakes 92 28g (1 cup) 21.1
Corn Chex 83 30g (1 cup) 20.8
Rice Krispies 82 33g (1.25 cup) 23
Corn pops 80 31g (1 cup) 22.4
Donut (lrg. glazed) 76 75g (1 donut) 24.3
Waffle (homemade) 76 75g (1 waffle) 18.7
Grape Nuts 75 58g (1/2 cup) 31.5
Bran Flakes 74 29g (3/4 cup) 13.3
Graham Cracker 74 14g (2 sqrs) 8.1
Cheerios 74 30g (1 cup) 13.3
Kaiser Roll 73 57g (1 roll) 21.2
Bagel 72 89g (1/4 in.) 33
Corn tortilla 70 24g (1 tortilla) 7.7
Melba Toast 70 12g (4 rounds) 5.6
Wheat Bread 70 28g (1 slice) 7.7
White Bread 70 25g (1 slice) 8.4
Kellogg’s Special K 69 31g (1 cup) 14.5
Taco Shell 68 13g (1 med) 4.8
Angel food cake 67 28g (1 slice) 10.7
Croissant, Butter 67 57g (1 med) 17.5
Muselix 66 55g (2/3 cup) 23.8
Oatmeal, Instant 65 234g (1 cup) 13.7
Rye bread, 100% whole 65 32g (1 slice) 8.5
Rye Krisp Crackers 65 25 (1 wafer) 11.1
Raisin Bran 61 61g (1 cup) 24.4
Bran Muffin 60 113g (1 med) 30
Blueberry Muffin 59 113g (1 med) 30
Oatmeal 58 117g (1/2 cup) 6.4
Whole wheat pita 57 64g (1 pita) 17
Oatmeal Cookie 55 18g (1 large) 6
Popcorn 55 8g (1 cup) 2.8
Pound cake, Sara Lee 54 30g (1 piece) 8.1
Vanilla Cake and Vanilla Frosting 42 64g (1 slice) 16
Pumpernickel bread 41 26g (1slice) 4.5
Chocolate cake w/chocolate frosting 38 64g (1 slice) 12.5
Gatorade Powder 78 16g (.75 scoop) 11.7
Cranberry Juice Cocktail 68 253g (1 cup) 24.5
Cola, Carbonated 63 370g (12oz can) 25.2
Orange Juice 57 249g (1 cup) 14.25
Carrot juice (freshly made) 43 250g 10
Hot Chocolate Mix 51 28g (1 packet) 11.7
Grapefruit Juice, sweetened 48 250g (1 cup) 13.4
Pineapple Juice 46 250g (1 cup) 14.7
Soy Milk 44 245g (1 cup) 4
Apple Juice 41 248g (1 cup) 11.9
Tomato Juice 38 243g (1 cup) 3.4
Baked Beans 48 253g (1 cup) 18.2
Pinto Beans 39 171g (1 cup) 11.7
Lima Beans 31 241g (1 cup) 7.4
Chickpeas, Boiled 31 240g (1 cup) 13.3
Lentils 29 198g (1 cup) 7
Kidney Beans 27 256g (1 cup) 7
Soy Beans 20 172g (1 cup) 1.4
Peanuts 13 146g (1 cup) 1.6
Potato 104 213g (1 med) 36.4
Parsnip 97 78g (1/2 cup) 11.6
Carrot, raw 92 15g (1 large) 1
Beets, canned 64 246g (1/2 cup) 9.6
Corn, yellow 55 166g (1 cup) 61.5
Sweet Potato 54 133g (1 cup) 12.4
Yam 51 136g (1 cup) 16.8
Peas, Frozen 48 72g (1/2 cup) 3.4
Tomato 38 123g (1 med) 1.5
Broccoli, cooked 0 78g (1/2 cup) 0
Cabbage, cooked 0 75g (1/2 cup) 0
Celery, raw 0 62g (1 stalk) 0
Cauliflower 0 100g (1 cup) 0
Green Beans 0 135g (1 cup) 0
Mushrooms 0 70g (1 cup) 0
Spinach 0 30g (1 cup) 0
Watermelon 72 152g (1 cup) 7.2
Pineapple, raw 66 155g (1 cup) 11.9
Cantaloupe 65 177g (1 cup) 7.8
Apricot, canned in light syrup 64 253g (1 cup) 24.3
Raisins 64 43g (small box) 20.5
Papaya 60 140g (1 cup) 6.6
Peaches, canned, heavy syrup 58 262g (1 cup) 28.4
Kiwi, w/ skin 58 76g (1 fruit) 5.2
Fruit Cocktail, drained 55 214g (1 cup) 19.8
Peaches, canned, light syrup 52 251g (1 cup) 17.7
Banana 51 118g (1 med) 12.2
Mango 51 165g (1 cup) 12.8
Orange 48 140g (1 fruit) 7.2
Pears, canned in pear juice 44 248g (1 cup) 12.3
Grapes 43 92g (1 cup) 6.5
Strawberries 40 152g (1 cup) 3.6
Apples, w/ skin 39 138g (1 med) 6.2
Pears 33 166g (1 med) 6.9
Apricot, dried 32 130g (1 cup) 23
Prunes 29 132g (1 cup) 34.2
Peach 28 98g (1 med) 2.2
Grapefruit 25 123g (1/2 fruit) 2.8
Plum 24 66g (1 fruit) 1.7
Sweet Cherries, raw 22 117g (1 cup) 3.7
Cashews 22
Almonds 0
Hazelnuts 0
Macademia 0
Pecans 0
Walnuts 0
Ice Cream (Lower Fat) 47 76g (1/2 cup) 9.4
Pudding 44 100g (1/2 cup) 8.4
Milk, Whole 40 244g (1 cup) 4.4
Ice Cream 38 72g (1/2 cup) 6
Yogurt, Plain 36 245g (1 cup) 6.1
Beef 0
Chicken 0
Eggs 0
Fish 0
Lamb 0
Pork 0
Veal 0
Deer-Venison 0
Elk 0
Buffalo 0
Rabbit 0
Duck 0
Ostrich 0
Shellfish 0
Lobster 0
Turkey 0
Ham 0


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[…] If we want to burn fat, we need to keep blood sugar levels and insulin low, as it stimulates synthesis of energy through fat and not through a stream of sugar from your food. This is part of why it is important to be aware and monitor food’s Glycemic Index. […]