GLOSSARY

Altitude Training Nutrition supports training and physiological adjustment at altitude. Energy supply, carbohydrate availability and appropriate assessment of iron status are relevant without implying routine supplementation for everyone.

Altitude preparation may require attention to energy supply, carbohydrate availability and iron status. Increased erythropoietic demand does not mean every athlete should take iron without assessment. Existing stores, health, dietary intake and the planned exposure matter, and excess iron can be harmful. Appetite and practical food access can complicate adequate intake. Nutrition supports the training and acclimatization plan, but no single food or supplement guarantees adaptation or removes the need for appropriate medical and performance support.

Heat, cold and altitude change the context in which athletes eat, drink and perform. Heat can increase thermal strain and modify tolerance; cold can increase heat-production costs under some conditions; altitude can affect appetite and other physiological demands. Responses depend on exposure, acclimatization and the task. A generic environmental label does not determine one universal energy or fluid prescription. Plan food access and recovery with the actual environment, clothing, workload and individual response in mind.

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.

Carbohydrate requirements vary with the intensity, duration and importance of the work. Daily intake relative to body mass describes a different quantity from an intake rate during exercise, which is commonly expressed per hour. A larger daily target does not mean the same amount should be consumed in every session. Match supply to the schedule, starting stores and practical tolerance, and distinguish grams eaten from grams absorbed or oxidized when discussing a fueling plan.

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.

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.