Paulin Scott, Roberts Justin, Roberts Michael, Davis Ian
School of Life and Medical Sciences, University of Hertfordshire, College Lane, Hatfield, Hertfordshire AL10 9AB UK.
Department of Life Sciences, Anglia Ruskin University, Cambridge Campus, East Road, Cambridge, CB1 1PT UK.
Extrem Physiol Med. 2015 Mar 12;4:3. doi: 10.1186/s13728-015-0022-0. eCollection 2015.
The nutritional demands of ultra-endurance racing are well documented. However, the relationship between nutritional consumption and performance measures are less obvious for athletes competing in Polar conditions. Therefore, the aim of this study was to evaluate dietary intake, hydration status, body composition and performance times throughout an 800-km Antarctic race.
The event organisers declared that 17 competitors would participate in the South Pole race. Of the 17 competitors, pre-race data were collected from 13 participants (12 males and 1 female (M ± SD): age: 40.1 ± 8.9 years; weight: 83.9 ± 10.3 kg; and body fat percentage: 21.9 ± 3.8%). Dietary recall, body composition and urinary osmolarity were assessed pre-race, midway checkpoint and end race. Data were compared on the basis of fast finishers (the Norwegian team (n = 3) who won in a record of 14 days) and slower finishers (the remaining teams (n = 10) reaching the South Pole between 22 and 28 days).
The percentage contribution of macronutrients to daily energy intake for all participants was as follows: carbohydrate (CHO) = 23.7% (221 ± 82 g.day(-1)), fat = 60.6% (251 ± 127 g.day(-1)) and protein = 15.7% (117 ± 52 g.day(-1)). Energy demands were closer met by faster finishers compared to slower finishers (5,332 ± 469 vs. 3,048 ± 1,140 kcal.day(-1), p = 0.02). Average reduction in body mass throughout the race was 8.3 ± 5.5 kg, with an average loss of lean mass of 2.0 ± 4.1 kg. There was a significant negative correlation between changes in lean mass and protein intake (p = 0.03), and lean mass and energy intake (p = 0.03). End-race urinary osmolarity was significantly elevated for faster finishers compared to slower finishers and control volunteers (faster finishers: 933 ± 157 mOsmol.L(-1); slower finishers: 543 ± 92 mOsmol.L(-1); control: 515 ± 165 mOsmol.L(-1), p = 0.04).
Throughout the race, both groups were subjected to a negative change in energy balance which partly explained reduced body mass. Carbohydrate availability was limited inferring a greater reliance on fat and protein metabolism. Consequently, loss in fat-free mass was more prevalent with insufficient protein and caloric intake, which may relate to performance.
超耐力比赛的营养需求已有充分记录。然而，对于在极地条件下参赛的运动员而言，营养摄入与运动表现指标之间的关系尚不明确。因此，本研究旨在评估一场800公里南极比赛全程的饮食摄入、水合状态、身体成分和比赛用时。
赛事组织者宣称17名参赛者将参加南极比赛。在这17名参赛者中，赛前数据收集自13名参与者（12名男性和1名女性（均值±标准差）：年龄：40.1±8.9岁；体重：83.9±10.3千克；体脂百分比：21.9±3.8%）。在赛前、中途检查点和比赛结束时评估饮食回忆、身体成分和尿渗透压。数据根据快速完赛者（挪威队（n = 3），以创纪录的14天获胜）和慢速完赛者（其余队伍（n = 10），在22至28天之间抵达南极）进行比较。
所有参与者宏量营养素对每日能量摄入的贡献百分比如下：碳水化合物（CHO）= 23.7%（221±82克·天⁻¹），脂肪 = 60.6%（251±127克·天⁻¹），蛋白质 = 15.7%（117±52克·天⁻¹）。与慢速完赛者相比，快速完赛者的能量需求得到了更接近的满足（5332±469 vs. 3048±1140千卡·天⁻¹，p = 0.02）。比赛全程体重平均下降8.3±5.5千克，去脂体重平均减少2.0±4.1千克。去脂体重变化与蛋白质摄入量（p = 0.03）以及去脂体重与能量摄入量（p = 0.03）之间存在显著负相关。与慢速完赛者和对照志愿者相比，快速完赛者比赛结束时的尿渗透压显著升高（快速完赛者：933±157毫摩尔·升⁻¹；慢速完赛者：543±92毫摩尔·升⁻¹；对照：515±165毫摩尔·升⁻¹，p = 0.04）。
在整个比赛过程中，两组的能量平衡均出现负向变化，这部分解释了体重下降的原因。碳水化合物供应有限，这意味着对脂肪和蛋白质代谢的依赖性更大。因此，蛋白质和热量摄入不足时，去脂体重的减少更为普遍，这可能与运动表现有关。
