This study implemented a 2-week high carbohydrate (CHO) diet intended to maximize CHO oxidation rates and examined the iron-regulatory response to a 26-km race walking effort. Twenty international-level, male race walkers were assigned to either a novel high CHO diet (MAX = 10 g/kg body mass CHO daily) inclusive of gut-training strategies, or a moderate CHO control diet (CON = 6 g/kg body mass CHO daily) for a 2-week training period. The athletes completed a 26-km race walking test protocol before and after the dietary intervention. Venous blood samples were collected pre-, post-, and 3 hr postexercise and measured for serum ferritin, interleukin-6, and hepcidin-25 concentrations. Similar decreases in serum ferritin (17–23%) occurred postintervention in MAX and CON. At the baseline, CON had a greater postexercise increase in interleukin-6 levels after 26 km of walking (20.1-fold, 95% CI [9.2, 35.7]) compared with MAX (10.2-fold, 95% CI [3.7, 18.7]). A similar finding was evident for hepcidin levels 3 hr postexercise (CON = 10.8-fold, 95% CI [4.8, 21.2]; MAX = 8.8-fold, 95% CI [3.9, 16.4]). Postintervention, there were no substantial differences in the interleukin-6 response (CON = 13.6-fold, 95% CI [9.2, 20.5]; MAX = 11.2-fold, 95% CI [6.5, 21.3]) or hepcidin levels (CON = 7.1-fold, 95% CI [2.1, 15.4]; MAX = 6.3-fold, 95% CI [1.8, 14.6]) between the dietary groups. Higher resting serum ferritin (p = .004) and hotter trial ambient temperatures (p = .014) were associated with greater hepcidin levels 3 hr postexercise. Very high CHO diets employed by endurance athletes to increase CHO oxidation have little impact on iron regulation in elite athletes. It appears that variations in serum ferritin concentration and ambient temperature, rather than dietary CHO, are associated with increased hepcidin concentrations 3 hr postexercise.

这项研究实施了为期 2 周的高碳水化合物 (CHO) 饮食，旨在最大限度地提高 CHO 氧化率，并检查了对 26 公里竞走努力的铁调节反应。20 名国际水平的男性竞走者被分配到新的高 CHO 饮食（MAX = 10 g/kg 体重每天 CHO）包括肠道训练策略，或适度的 CHO 控制饮食（CON = 6 g/kg 体重）每天大量 CHO），为期 2 周的培训期。运动员在饮食干预前后完成了 26 公里竞走测试方案。在运动前、运动后和运动后 3 小时收集静脉血样本，并测量血清铁蛋白、白细胞介素 6 和铁调素 25 的浓度。在 MAX 和 CON 干预后，血清铁蛋白（17-23%）也出现了类似的下降。在基线处，与 MAX（10.2 倍，95% CI [3.7, 18.7]）相比，CON 在步行 26 公里（20.1 倍，95% CI [9.2, 35.7]）后白细胞介素 6 水平的运动后增加更大。运动后 3 小时铁调素水平也有类似的发现（CON = 10.8 倍，95% CI [4.8, 21.2]；MAX = 8.8 倍，95% CI [3.9, 16.4]）。干预后，IL-6 反应（CON = 13.6 倍，95% CI [9.2, 20.5]；MAX = 11.2 倍，95% CI [6.5, 21.3]）或铁调素水平（CON =饮食组之间的 7.1 倍，95% CI [2.1, 15.4]；MAX = 6.3 倍，95% CI [1.8, 14.6])。较高的静息血清铁蛋白（95% CI [3.9, 16.4]）。干预后，IL-6 反应（CON = 13.6 倍，95% CI [9.2, 20.5]；MAX = 11.2 倍，95% CI [6.5, 21.3]）或铁调素水平（CON =饮食组之间的 7.1 倍，95% CI [2.1, 15.4]；MAX = 6.3 倍，95% CI [1.8, 14.6])。较高的静息血清铁蛋白（95% CI [3.9, 16.4]）。干预后，IL-6 反应（CON = 13.6 倍，95% CI [9.2, 20.5]；MAX = 11.2 倍，95% CI [6.5, 21.3]）或铁调素水平（CON =饮食组之间的 7.1 倍，95% CI [2.1, 15.4]；MAX = 6.3 倍，95% CI [1.8, 14.6])。较高的静息血清铁蛋白（p  = .004) 和较热的试验环境温度 ( p  = .014) 与运动后 3 小时较高的铁调素水平相关。耐力运动员为增加 CHO 氧化而采用的非常高的 CHO 饮食对精英运动员的铁调节影响很小。似乎血清铁蛋白浓度和环境温度的变化，而不是饮食中的 CHO，与运动后 3 小时铁调素浓度的增加有关。