You’ve likely seen or read the term GI or glycemic index before. You may have even heard some fuss about it pertaining to runners and athletic performance, but is the fuss really warranted or is GI fuelling really more about picky eaters?

Glycemic index is a ranking system for foods based on the rate at which they release energy into the bloodstream. Foods are ranked from 1 to 100 according to how fast they are absorbed, which can be useful when planning your fuelling strategy for your run training and races.

There are two main categories of GI foods – high GI foods and low GI foods:

High GI foods are rapidly absorbed by the body and provide a quick source of energy. Examples include glucose, sugars, and refined products such as white bread, cakes and bagels.

Low GI foods are absorbed much slower by the body and provide a more sustained source of energy. Examples include oatmeal, whole grains and many vegetables.

Practicing good GI eating really can make a difference in your run training and racing performance. During your run, you burn calories and the farther or faster you run, the more calories you use. To effectively replenish your fuel stores, you need to eat carbohydrates. Carbohydrates can be either high or low GI.

To maximize training and performance, tailor your fuelling habits based on glycemic index. Before you run, eat low GI foods that will provide a sustained energy release during the run. Post-run eat both high and low GI foods to maximize your recovery.

To make the most of following glycemic recommendations and really reap the benefits in training be sure to properly balance your nutrition plan. This means;

- Including a small amount of fat (try to avoid saturated fats) in each meal to help slow down gastric emptying, further sustaining energy levels.

- Including lean protein with each meal, which will also slow transit time from the stomach and encourages lean muscle mass.

- Including lots of fruit and fiber in your diet. Making your meals fiber rich through whole grains, fruits and vegetables helps slow the absorption of glucose into the blood.

- Reducing your cooking times because the longer you cook carbohydrate-rich foods, particularly pastas, the more they break down into simple sugars, and the faster they are absorbed.

- Eating slightly unripe fruits. Not to the point where it is bitter but, the riper a piece of fruit is, the more simple sugars it contains. Less ripe fruit contains more complex carbohydrates and will therefore have a lower GI.

For running fuel and performance, following a GI plan or at least making changes to become more aware of your foods’ glycemic index is a good idea. Running requires slow-release energy and because the foundation of any GI eating plan is on always eating complex carbohydrates, it will optimize your running-specific nutrition, which means that you are giving yourself the best chance of performing well.