High glycemic index foods: fueling endurance athletes, and causing obesity amongst the sedentary.
The glycemic index is a ranking of all carbohydrate containing foods. It is kind of a measure of how a food will effect your blood sugar.
So here is the deal. The more refined a carb is, the quicker it is digested, and the quicker it gets to your blood stream.
Take fruit juice for example. It is all sugar, and requires very little digestion. This will spike your blood sugar faster than a slice of bread or a potato because the starch in the bread and potato has to be broken down before it is absorbed.
Why do we care about this?
During a demanding bout of exercise, you need to keep the fuel coming. This is why endurance enthusiasts rely so heavily on sugary products like Gatorade and Gu. These kind of products are made to provide quick fuel. They get sugar into your blood stream as quick as possible so you have fuel ready to go.
Let me also fill you in on when you DON’T want high glycemic index foods. Pretty much all the rest of the time.
Eating too many high glycemic foods without exercising will just make you fat. For normal everyday eating, we should all be looking for high fiber sources of carbohydrates. Fiber can prevent a spike in blood sugar.
Low glycemic index foods are complex carbs with lots of fiber. Oatmeal, high fiber breads, and brown rice. These are good for always. (Assuming you use good portion control.)
High glycemic index foods are refined carbs. These are low fiber foods usually containing sugar or are made white flour. These are great before and during exercise.
So there you have it. Now there is no excuse for you to bonk on a long bike ride. The glycemic index is your friend. Use it wisely.