The Glycemic Index (or GI) has quickly been gaining recognition through the relatively recent popularity of low-carbohydrate diets, as well as its use in regulating blood sugar. The Glycemic Index ranks different sources of carbohydrates based on their effect on blood glucose levels. Foods with high glycemic index rankings can raise blood glucose and insulin levels rapidly. In contrast, foods with low GIs have little effect on blood glucose and insulin levels. Pure glucose is assigned a value of 100, and foods are given a number according to their relative effect on blood glucose levels.
The GI Scale
For example, the Glycemic Index of white bread is 71. This means that white bread raises blood glucose levels 71 percent as much as pure glucose. Generally, foods with a ranking 55 and under are considered low glycemic index foods, foods within the 55-70 range are mid-glycemic index, and those 70 and over are considered high GI foods.
Diet & Energy
The Glycemic Index affects several components of bodybuilding. First, it is important to note that when more low glycemic index foods are consumed, energy levels are sustained (and insulin levels remain in check), rather than experiencing the peeks and valleys that many dieters complain about when cutting back on their caloric intake. This is due to the fact that that lower GI foods tend to keep you fuller, longer. Consuming high GI foods results in a temporary surge in energy, followed by a "crash," leaving you feeling tired and hungry.
It is important to maintain consistent levels of energy when training intensely. Having a tool like the Glycemic Index allows us to better evaluate our dietary habits. Research has shown that combining a larger amount of carbohydrates with moderate amounts of protein and fat allow quicker and greater results than a high carbohydrate diet.
Incorporating low GI foods into your diet also has benefits in the way we store fat. When your insulin index is lower, it makes it easier to burn fat. It also makes it more difficult to store fat. This is extremely important for bodybuilders, as a thick layer of fat on top of the muscle will prohibit it from showing when at rest.
When to Turn to High GI Foods
High Glycemic Index foods do have their place in a bodybuilder's nutritional plan. Glycogen stores are depleted after intense training sessions, and can quickly be restored by consuming higher GI foods. Blood flow to the muscles increases in the few hours after a heavy workout. High Glycemic Index foods allows glycogen to synthesize quicker during this time, so it is vital to take advantage of this window.
Being familiar with the Glycemic Index is imperative for bodybuilders who wish to utilize their time and efforts most effectively. Knowing which foods have high, moderate and low GI's allows you to plan your diet in a way that will maintain consistent energy and insulin levels, help keep you satisfied longer (helping to keep you from cheating), and ensure the quickest, best results possible.