GLOSSARY

Pre-Exercise Glycemic Response is the change in circulating glucose after the pre-exercise food, influenced by the meal and individual physiology.

Carbohydrate eaten before exercise can raise glucose and insulin before muscular glucose uptake increases with activity. Some individuals develop a transient fall in glucose around the transition, but symptoms and performance effects vary. A laboratory glucose dip does not automatically establish a clinical disorder. Rehearsing the timing and composition can identify a tolerable approach. Recurrent or severe symptoms need assessment, especially in athletes using glucose-lowering medication, rather than repeated unsupervised experimentation.

The pre-exercise meal contributes to starting fuel availability and comfort. A larger meal generally needs more time before strenuous movement than a small snack, but digestion is not governed by one fixed clock. Food volume, fat, fiber, exercise intensity and individual tolerance all matter. Familiar carbohydrate-containing foods can be useful before demanding exercise. Adjusting a particular meal for comfort is different from removing fiber or fat from the athlete's everyday diet.

Muscle and liver glycogen have related but different roles. Muscle glycogen supplies the muscle in which it is stored, while liver glycogen helps support blood glucose. An overnight fast can reduce liver carbohydrate availability without producing the same depletion in every muscle. Starting concentration, recruited fibers and exercise demand affect use. An estimate of total stores does not directly describe the availability of every local glycogen pool during a specific movement.