GLOSSARY

Protein and Immune Recovery relates adequate protein and amino-acid supply to normal immune function during recovery, without implying that extra protein prevents illness.

Exercise changes the distribution and activity of immune cells, but a transient laboratory change does not by itself establish increased infection risk. Sufficient energy, carbohydrate when appropriate, protein and micronutrients support normal immune function. Sleep, travel, exposure and training load also matter. More of an immune-related nutrient is not automatically better, and a supplement cannot guarantee protection from illness. Persistent symptoms require appropriate evaluation rather than being attributed solely to a supposed post-exercise immune window.

Energy requirements depend on body size and composition, activity, life stage and physiological circumstances. A maintenance estimate is a starting point for a defined situation rather than a permanent personal calorie ceiling. Training load, recovery, appetite and changes in body mass help evaluate its usefulness. Growth, illness or a change in training schedule may require reassessment. Adequate energy also needs appropriate carbohydrate, protein, fat and micronutrient provision; matching a calorie total alone does not guarantee a balanced sports diet.

Energy availability describes dietary energy remaining after exercise expenditure, expressed relative to fat-free mass over a defined period. It differs from whole-day energy balance and from body-fat percentage. Calculations are sensitive to errors in food records, exercise expenditure and body-composition estimates. No single threshold or short observation establishes a diagnosis for every athlete. Persistent fatigue, impaired recovery or other concerning changes warrant assessment in the broader health and training context rather than a conclusion from one calculated value.

Recovery can be organized around refueling, repairing, rehydrating and resting. These priorities overlap but do not finish at the same time. Glycogen, protein turnover, fluid balance, nervous-system readiness and tissue symptoms can recover at different rates. The next session determines the practical urgency. An early snack may bridge a short interval, while subsequent meals and sleep complete the broader plan. Successful recovery is demonstrated by health and readiness for the intended work, not merely by consuming a branded product.

Sleep supports recovery and cannot be replaced by a nutrient or drink. Protein consumed before sleep can provide amino acids overnight and may be useful when it helps meet the athlete's daily needs. Evidence from particular training studies does not establish that everyone needs a bedtime supplement or that casein is mandatory. Consider the evening meal, total protein, gastrointestinal comfort and sleep quality. Late caffeine, very large meals or excessive drinking can interfere with the recovery goal.

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.