Schalt Adriane, Johannsen Michelle M, Kim Jimin, Chen Richard, Murphy Carl J, Coker Melynda S, Gunga Hanns-Christian, Coker Robert H, Steinach Mathias
Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, United States.
Charité - Universitätsmedizin Berlin, Institute of Physiology, Center for Space Medicine and Extreme Environments Berlin, Berlin, Germany.
Front Physiol. 2018 Dec 20;9:1761. doi: 10.3389/fphys.2018.01761. eCollection 2018.
The objective of this study was to determine alterations in caloric balance, body composition, metabolites, and cytokines in athletes participating in the Yukon Arctic Ultra. Ten participants traveling on foot in the 2017 692-km event were recruited for the study. Measurements and samples were obtained at pre-event, 278 km (C1), 384 km (C2), and post-event. Body composition measurements were obtained using bioelectrical impedance analysis. Accelerometer devices were utilized to provide an estimation of caloric expenditure and dietary recalls provided assessments of caloric intake. Blood serum samples were collected, processed, and analyzed using enzyme-linked immunosorbent assays or nuclear magnetic resonance. Results were analyzed using linear mixed model, presented as means ± SD, and considered significant at < 0.05. Participants (8 males, 2 females; age: 37 ± 10 years; body mass index: 24.4 ± 2.5 kg/m) were recruited. Four males and one female completed the entire event in 260 ± 19 h. Caloric intake/expenditure was 4,126 ± 1,115 kcal/day and 6,387 ± 781 kcal/day, respectively, indicating a caloric deficit of 2,261 ± 1,543 kcal/day. Total mass, body mass index, and fat mass were reduced at each time point of the event. Fat-free mass (FFM) was unchanged throughout the event. Follistatin was increased at C1 (1,715 ± 876 pg/ml) in comparison to baseline. Acetoacetate increased significantly at post-event (6.1 ± 1.5 mg/ml). Despite a pronounced caloric deficit and sustained activity under extreme cold conditions, FFM was preserved with an increase in serum follistatin and acetoacetate. Future studies should be directed at the role of nutrient strategies and/or training methods on the retention of FFM under these conditions.
本研究的目的是确定参加育空北极超级马拉松的运动员在热量平衡、身体成分、代谢物和细胞因子方面的变化。招募了10名参加2017年692公里赛程徒步比赛的参与者进行研究。在赛前、278公里（C1）、384公里（C2）和赛后进行测量并采集样本。使用生物电阻抗分析获取身体成分测量数据。利用加速度计设备估算热量消耗，并通过饮食回顾评估热量摄入。采集血清样本，进行处理，并使用酶联免疫吸附测定或核磁共振进行分析。结果采用线性混合模型进行分析，以均值±标准差表示，P<0.05时被认为具有显著性。招募的参与者（8名男性，2名女性；年龄：37±10岁；体重指数：24.4±2.5kg/m²）。4名男性和1名女性在260±19小时内完成了整个赛程。热量摄入/消耗分别为4126±1115千卡/天和6387±781千卡/天，表明每日热量缺口为2261±1543千卡。在赛程的每个时间点，总体重、体重指数和脂肪量均有所下降。无脂肪量（FFM）在整个赛程中保持不变。与基线相比，卵泡抑素在C1时升高（1715±876pg/ml）。乙酰乙酸在赛后显著升高（6.1±1.5mg/ml）。尽管存在明显的热量缺口且在极端寒冷条件下持续活动，但FFM得以保留，同时血清卵泡抑素和乙酰乙酸增加。未来的研究应针对营养策略和/或训练方法在这些条件下对FFM保留的作用展开。
