Loucks Anne B
Department of Biological Sciences, Ohio University, Athens, OH 45701-2979, USA.
J Sports Sci. 2004 Jan;22(1):1-14. doi: 10.1080/0264041031000140518.
Many athletes, especially female athletes and participants in endurance and aesthetic sports and sports with weight classes, are chronically energy deficient. This energy deficiency impairs performance, growth and health. Reproductive disorders in female athletes are caused by low energy availability (defined as dietary energy intake minus exercise energy expenditure), perhaps specifically by low carbohydrate availability, and not by the stress of exercise. These reproductive disorders can be prevented or reversed by dietary supplementation in compensation for exercise energy expenditure without any moderation of the exercise regimen. Energy balance is not the objective of athletic training. To maximize performance, athletes strive to achieve an optimum sport-specific body size, body composition and mix of energy stores. To pursue these objectives, athletes need to manage fat, protein and carbohydrate balances separately, but it is impractical for athletes to monitor these balances directly, and appetite is not a reliable indicator of their energy and macronutrient needs. To guide their progress, athletes need to eat by discipline and to monitor specific, reliable and practical biomarkers of their objectives. Skinfolds and urinary ketones may be the best biomarkers of fat stores and carbohydrate deficiency, respectively. Research is needed to identify and validate these and other markers.
许多运动员，尤其是女性运动员以及耐力项目、审美类项目和有体重级别的项目的参与者，长期处于能量不足状态。这种能量不足会损害运动表现、生长发育和健康。女性运动员的生殖紊乱是由能量可利用性低（定义为膳食能量摄入减去运动能量消耗）引起的，可能具体是由碳水化合物可利用性低导致的，而非运动压力所致。通过膳食补充来补偿运动能量消耗，而无需调整运动方案，这些生殖紊乱就可以得到预防或逆转。能量平衡并非运动训练的目标。为了使运动表现最大化，运动员努力实现特定于某项运动的最佳体型、身体成分和能量储备组合。为了追求这些目标，运动员需要分别管理脂肪、蛋白质和碳水化合物的平衡，但运动员直接监测这些平衡是不切实际的，而且食欲也不是其能量和宏量营养素需求的可靠指标。为了指导自己的进展，运动员需要有规律地饮食，并监测与其目标相关的特定、可靠且实用的生物标志物。皮褶厚度和尿酮可能分别是脂肪储备和碳水化合物缺乏的最佳生物标志物。需要开展研究来识别和验证这些及其他标志物。
