GLOSSARY

Supplement Screening Questionnaire evaluates whether a supplement addresses a real need and whether its evidence, safety and quality fit the athlete's circumstances.

A supplement can address a defined nutrient shortfall, provide a convenient sports-food format or target a specific performance mechanism. These purposes require different evidence and assessment. A product is not necessary simply because it is marketed to athletes, and normal training fatigue does not identify a nutrient deficiency. Begin with the athlete's diet, health, training and practical constraints, then define the expected benefit, suitable outcome and stopping or review point before adding a product.

A credible supplement claim needs relevant controlled evidence, an appropriate comparison and a meaningful outcome. Randomization, placebo control and blinding reduce different sources of bias but do not guarantee a useful result. Sample size, uncertainty, training status, sex, diet and protocol affect interpretation. A pooled estimate is not a promise to every individual. Mechanistic plausibility, a changed biomarker, exercise capacity and actual competition performance are distinct levels of information that should not be treated as interchangeable.

For example, identify the problem a supplement is intended to solve before choosing a product. A convenient food format, correction of a documented shortfall and an attempted performance benefit require different assessments. Check the exact ingredient, useful outcome, health context and product quality, then set a reasonable review point rather than continuing indefinitely because the product is marketed for athletes.

The dose refers to the amount of the relevant active ingredient, not necessarily the mass of powder or the number of scoops. A single dose, daily total and body-mass-relative dose describe different quantities. Larger amounts can increase adverse effects without improving performance. Loading, maintenance and acute timing are ingredient-specific strategies rather than universal rules. Check all products used together so that repeated ingredients do not create an unintended total intake.