When foods containing starches, also known as complex carbohydrates, are consumed, the body breaks the starches down into glucose. Glucose is the substance the body uses to create immediate bursts of energy.
Starches are most commonly found in grains and breads and are an abundant source of energy for the body. The process of breaking down starches in the body begins in the mouth. Saliva, along with chewing, literally breaks the food down into small pieces that are able to be processed easily by the stomach. Saliva also contains enzymes that begin breaking down starches on a cellular level, converting them into maltose.
Maltose is a carbohydrate that is more easily processed by the body. Once the food is swallowed and passed into the stomach, various acids and enzymes go to work on deconstructing the maltose and converting it into glucose.
If the body is in need of any glucose for energy, it immediately passes it into the bloodstream after conversion. The unused portions are converted into a compound called glycogen for long-term storage. The body always uses any freshly produced glucose for energy before restoring the glycogen reserves. Converting glycogen to energy is more taxing than glucose, which is why many athletes consume starches and other carbohydrates a few hours before exercising.