Mujika Iñigo, Bourdillon Nicolas, Zelenkova Irina, Vergnoux Frédéric, Millet Grégoire P
Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country, Leioa, Spain.
Exercise Science Laboratory, School of Kinesiology, Faculty of Medicine, Universidad Finis Terrae, Santiago, Chile.
Front Physiol. 2024 Sep 23;15:1474479. doi: 10.3389/fphys.2024.1474479. eCollection 2024.
Elite swimmers often schedule altitude training camps ahead of major events in an attempt to maximize performance. However, the relationships between altitude-induced hematological changes, markers of training adaptation, and performance changes in such context are unclear. This study assessed hematological status, markers of daily adaptation, and swimming performance in elite middle-distance and distance swimmers during a 22-day altitude training camp at 2,320 m, 2 weeks prior to World Championship qualification competition.
Venous blood was obtained and total hemoglobin mass (tHb) measured (CO rebreathing) in 7 elite swimmers (4 females, 3 males) 8 days before and on day 22 of the altitude camp. Resting heart rate, peripheral oxygen saturation, urinary specific gravity, body mass, fatigue and self-reported sleep duration and quality were monitored daily during the altitude camp. Swimming performance was assessed through a standardized set (6 sets of 4 maximal repetitions of 100 m front crawl) on days 3, 10 and 17 of the camp, and at sea level competitions (200 m-1,500 m) immediately after the camp, and 2 weeks later.
tHb (+5.6 ± 3.3%; range: 2.1%-11.0%; < 0.05), red blood cell count, hemoglobin concentration, hematocrit increased at the end of the training camp ( < 0.05). Performance at altitude improved throughout the camp (+1.4 ± 0.4%; range: 0.7%-2.5%; < 0.05). No significant relationship was noted between hematological changes, the change in altitude performance and any of the monitored daily markers of adaptation during the camp. Compared to the swimmers' previous personal best, competition performances did not improve immediately (2.5% ± 1.9% slower times) and 2 weeks after altitude (1.2% ± 1.4% slower times).
The 22-day altitude training camp at 2,320 m was beneficial for elite swimmers' tHb, hematological status and performance at altitude, but these benefits did not clearly translate into enhanced sea level performance immediately after or 2 weeks later. The present study confirms the large inter-individual variability in hematological responses to altitude training, and that the improvement in performance at altitude and sea level may depend on factors other than the increase in tHb alone.
优秀游泳运动员常在重大赛事前安排高原训练营，以期最大限度提高成绩。然而，在这种情况下，高原诱导的血液学变化、训练适应性标志物与成绩变化之间的关系尚不清楚。本研究评估了7名优秀中长距离游泳运动员在海拔2320米的22天高原训练营期间（在世锦赛资格赛2周前）的血液学状况、每日适应性标志物及游泳成绩。
在高原训练营第8天和第22天，采集7名优秀游泳运动员（4名女性，3名男性）的静脉血，采用一氧化碳重呼吸法测量总血红蛋白量（tHb）。在高原训练营期间，每天监测静息心率、外周血氧饱和度、尿比重、体重、疲劳程度以及自我报告的睡眠时间和质量。在训练营第3天、第10天和第17天，以及训练营结束后立即在海平面比赛（200米至1500米）和2周后，通过标准化组（6组，每组4次100米自由泳最大重复次数）评估游泳成绩。
训练营结束时，tHb增加（+5.6±3.3%；范围：2.1%-11.0%；P<0.05），红细胞计数、血红蛋白浓度、血细胞比容升高（P<0.05）。整个训练营期间，高原成绩提高（+1.4±0.4%；范围：0.7%-2.5%；P<0.05）。在训练营期间，血液学变化、高原成绩变化与任何监测的每日适应性标志物之间均未发现显著关系。与游泳运动员之前的个人最好成绩相比，比赛成绩在训练营结束后即刻未提高（慢2.5%±1.9%），在高原训练2周后也未提高（慢1.2%±1.4%）。
在海拔2320米进行的22天高原训练营对优秀游泳运动员的tHb、血液学状况和高原成绩有益，但这些益处并未在训练营结束后即刻或2周后明显转化为海平面成绩的提高。本研究证实了个体对高原训练的血液学反应存在较大差异，且高原和海平面成绩的提高可能取决于tHb增加以外的其他因素。
