GLOSSARY

Rebound Hypoglycemia describes a fall to low glucose after preceding intake, sometimes around exercise onset. Symptoms and verified measurements require contextual assessment.

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.

Exogenous carbohydrate comes from food or drink, while endogenous carbohydrate comes from existing body stores. Digestion, intestinal absorption, circulation, muscle uptake and oxidation are separate steps. Tracer studies can estimate oxidation of ingested substrate under defined assumptions. The amount consumed is not the amount oxidized immediately, and a high measured oxidation rate does not alone prove better race performance. Specify the substrate source and the process measured before comparing research or planning intake.

Gut training means practicing the intended food and fluid strategy during suitable training sessions and progressing according to tolerance. Repeated exposure may improve comfort or handling, but symptom improvement does not directly prove increased transporter expression in an individual. Glucose and fructose transport involve different proteins and their adaptation is a specific research question. Record actual intake, conditions and symptoms. A very high intake used successfully by one athlete should not be treated as the starting requirement for everyone.

A nutritional strategy should be evaluated by the quality and relevance of evidence, the athlete's response and the feasibility of implementation. Molecular signaling, a substrate-oxidation change, a laboratory capacity test and race performance are different outcomes. Association does not establish cause, and a response in one small study need not generalize to all athletes. Define the intended benefit before changing the plan, then evaluate training quality, recovery and performance under comparable circumstances rather than judging success by novelty.