Dietary intake in high-level swimmers. A 32-week prospective cohort study

Abstract AIMS To determine whether high-level swimmers present adequate energy and macronutrient intake during each training phase of the season. METHODS A 32-week prospective cohort study was conducted with 18 elite swimmers (10 men, 20±2 years; 8 women, 20±3 years) from a competitive swimming club. This period comprised two training macrocycles, each one divided in four training phases: general, mixed, specific and competition. Dietary intake, estimated energy expenditure and daily energy requirements were assessed in every training phase. Body composition was evaluated five times throughout the season. Energy and macronutrient consumption were compared with the energy expenditure and the literature recommendations, respectively. RESULTS Athletes maintained a relatively constant dietary intake throughout the season, regardless the different needs of each training phase. The balance between energy consumption and expenditure was negative in all training phases (p=0.02; d between 1.5-6.2) for women, while men did so in half of phases (p<0.01; d between 0.3-4.1). Swimmers had higher protein intake than recommendations in 73% of the evaluations, while carbohydrate and lipids intake were lower than recommendations in 76% and 69% of the evaluations, respectively. CONCLUSION Athletes did not meet the energy demands and specific macronutrient requirements of each training phase of the competitive season.

摘要
目的：明确高水平游泳运动员在赛季各训练阶段能否获得充足的能量与宏量营养素（macronutrient）摄入。
方法：本研究为一项为期32周的前瞻性队列研究，招募了某竞技游泳俱乐部的18名优秀游泳运动员（男性10名，年龄20±2岁；女性8名，年龄20±3岁）。整个研究周期包含2个训练大周期，每个大周期均划分为4个训练阶段：一般训练阶段、混合训练阶段、专项训练阶段及竞赛阶段。在每个训练阶段均对受试者的膳食摄入、估计能量消耗（estimated energy expenditure）及每日能量需求进行评估。整个赛季期间共开展5次身体成分（body composition）评估。将能量摄入与能量消耗进行对比，宏量营养素摄入则分别与文献推荐摄入量进行比对。
结果：尽管各训练阶段的营养需求存在差异，但运动员在整个赛季的膳食摄入均保持相对稳定。女性运动员在所有训练阶段均出现能量摄入与消耗的负平衡（p=0.02；效应量d介于1.5~6.2），而男性运动员仅在半数训练阶段出现该情况（p<0.01；效应量d介于0.3~4.1）。73%的评估结果显示，游泳运动员的蛋白质摄入高于推荐标准，而碳水化合物与脂肪摄入分别在76%和69%的评估中低于推荐标准。
结论：竞技游泳运动员未能满足赛季各训练阶段的能量需求与特定宏量营养素摄入要求。