Practical Application of Altitude/Hypoxic Training for Olympic Medal Performance:The Team USA Experience

Although scientific conclusions remain equivocal,there is evidence-based research,as well as anecdotal support,suggesting that altitude training can enhance performance among Olympic level athletes,particularly in endurance sport.This appears to be due primarily to hypoxia-induced increases in total hemoglobin mass and subsequent improvements in maximal oxygen uptake and other factors contributing to aerobic performance.Although less clear,it is possible that non-hematological adaptations may contribute secondarily to improvements in post-altitude performance.These physiological effects are most likely realized when the altitude exposure is of sufficient“hypoxic dose”to provide the necessary stimuli for performance-affecting changes to occur via hypoxia-inducible factor 1α(HIF-1α)and hypoxia-inducible factor 2α(HIF-2α)pathways and their downstream molecular signaling.Team USA has made a strong commitment over the past 20 years to utilizing altitude training for the enhancement of performance in elite athletes in preparation for the Olympic Games and World Championships.Team USA’s strongest medal-producing Olympic sports-USA Swimming and USA Track and Field-embraced altitude training several years ago,and they continue to be leaders within Team USA in the practical and successful application of altitude training.Whereas USA Swimming utilizes traditional“live high and train high”(LH+TH)altitude training,USA Track and Field tends more toward the use of the altitude training strategy whereby athletes live high(and potentially sleep higher,either naturally or via simulated altitude),while training high during moderate-intensity(<lactate threshold 2)training sessions,and train low during high-intensity(>lactate threshold 2)training sessions(LH+TH_([<LT])+TL_([>LT])).Although USA Swim-ming and USA Track and Field have taken different approaches to altitude training,they have been equally successful at the Olympic Games and World Championships,both teams being ranked first in the world based on medals earned in these major international competitions.In addition to USA Swimming and USA Track and Field,several other Team USA sports have had consistently competitive performance results in conjunction with regular and systematic altitude training blocks.The purpose of this paper was to describe select altitude training strategies used by Team USA athletes,and the impact of those strategies on podium performance at major international competitions,specifically the Olympic Games and World Championships.

Do PON1-Q192R and PON1-L55M polymorphisms modify the effects of hypoxic training on paraoxonase and arylesterase activity?

Background:Low levels of antioxidant paraoxonase 1(PON 1)enzyme activity,PON1-Q192R polymorphism(a glutamine(Q)to arginine(R)substitution at position 192),PON1-L55M polymorphism(a leucine(L)to methionine(M)substitution at position 55),and oxidized low-density lipoprotein(oxLDL)are risk factors for coronary heart disease.Aerobic exercise improves PON1 activity,but the effects of hypoxic exercise are yet unclear.The aim of this study was to determine the effects of hypoxic underwater rugby training on PON1 activity and oxLDL levels and the role of the mentioned polymorphisms.Methods:Serum PON1 and arylesterase activities(ARE),PON1,PON3,and oxLDL protein levels(by using the enzyme-linked immunosorbent assays)were determined in an athletic group(42 trained male underwater rugby players;age=21.7±4.2 years,mean±SD)and a control group(43 sedentary men;age=23.9±3.2 years).The polymorphisms were determined from genomic DNA samples.Results:PON1 activity(25.1%,p=0.052),PON3(p<0.001),and oxLDL(p<0.001)of the athletic group,including most genotype groups,were higher than those of the control group.In comparison to the controls,PON1 activity levels(p=0.005)of the PON1-Q192R homozygote QQ genotype group and PON1 activity levels(30%,p=0.116)of the PON1-L55M homozygote LL genotype group were higher,whereas ARE activity values of athletic R allele carrier(Rc=QR+RR)(p=0.005)and LL group(p=0.002)were lower than the control genotype groups related to their polymorphisms.Conclusion:Hypoxic training can cause(1)significant oxidative stress,including oxLDL,and an antioxidant response(increase in PON1 activity and PON3),(2)differences in the activity of PON1 and ARE,which are modified by PON1-Q192R and PON1-L55M polymorphisms,respectively,and(3)improvements in PON1 activity of QQ and LL groups.However,hypoxic training can cause a disadvantage of LL and Rc groups for ARE.

Hypoxic training methods for improving endurance exercise performance

Endurance athletic performance is highly related to a number of fiactors that can be altered through altitude and hypoxic training including increases in erythrocyte volume, maximal aerobic exercise capacity, capillary density, and economy. Physiological adaptations in response to acute and chronic exposure to hypoxic environments are well documented and range from short-term detrimental effects to longer-term adaptations that can improve performance at altitude and in sea-level competitions. Many altitude and hypoxic training protocols have been developed, employing various combinations of living and training at sea-level, low, moderate, and high altitudes and utilizing natural and artificial altitudes, with varying degrees of effectiveness. Several factors have been identified that are associated with individual responses to hypoxic training, and techniques for identifying those athletes most likely to benefit from hypoxic trairdng continue to be investigated. Exposure to sufficiently high altitude （2000-3000 m） for more than 12 h/day, while training at lower altitudes, for a minimum of 21 days is recommended. Timing of altitude training related to competition remains under debate, although general recommendations can be considered.

Effects of hypoxic training on physiological exercise intensity and recognition of exercise intensity in young men

This study aimed to examine the effects of hypoxic training on physiological exercise intensity and recognition of exercise intensity in young men. The participants included 9 healthy young males (23.2 ± 6.5 years old, 176.2 ±6.7 cm, 74.3 ±16.4 kg). VO2 was measured during running with subjective exercise intensities of “somewhat hard” for 3 min and “fairly light” for 3 min. After the measurements, the participants answered the question “what percentage of your maximal effort was performed during both running exercises.” The exercise intensity recognition for the “fairly light” and “somewhat hard” intensities and the physiological exercise intensity measured by relative VO2 (%) and relative heart rate (HR, %) were then evaluated. The hypoxic training was performed 3 times a week for 4 weeks in a normobaric hypoxic chamber?(oxygen concentration, 15.4% and altitude, 2500 m). The participants ran at an exercise intensity of 60% VO2max for 40 min after a 5 min warm-up and then performed a 5 min cool-down. After training, they sat on a chair in the same room for 30 min. VO2max and HRmax changed significantly after the training. At “fairly light” intensity, the physiological measures were significantly higher than recognition of exercise intensity, with relative VO2 (%) increasing after training. In conclusion, hypoxia training causes an increase in VO2max and physiological exercise intensity during running at a “fairly light” intensity.

Immune consequences of exercise in hypoxia:A narrative review

Immune outcomes are key mediators of many health benefits of exercise and are determined by exercise type,dose(frequency/duration,intensity),and individual characteristics.Similarly,reduced availability of ambient oxygen(hypoxia)modulates immune functions depending on the hypoxic dose and the individual capacity to respond to hypoxia.How combined exercise and hypoxia(e.g.,high-altitude training)sculpts immune responses is not well understood,although such combinations are becoming increasingly popular.Therefore,in this paper,we summarize the impact on immune responses of exercise and of hypoxia,both independently and together,with a focus on specialized cells in the innate and adaptive immune system.We review the regulation of the immune system by tissue oxygen levels and the overlapping and distinct immune responses related to exercise and hypoxia,then we discuss how they may be modulated by nutritional strategies.Mitochondrial,antioxidant,and anti-inflammatory mechanisms underlie many of the adaptations that can lead to improved cellular metabolism,resilience,and overall immune functions by regulating the survival,differentiation,activation,and migration of immune cells.This review shows that exercise and hypoxia can impair or complement/synergize with each other while regulating immune system functions.Appropriate acclimatization,training,and nutritional strategies can be used to avoid risks and tap into the synergistic potentials of the poorly studied immune consequences of exercising in a hypoxic state.

High-altitude gastrointestinal bleeding:An observation in Qinghai-Tibetan railroad construction workers on Mountain Tanggula

AIM: To investigate the gastrointestinal bleeding (GIB) in people from lowland to high altitude and in workers on Mountain Tanggula and its causes as well as treatment and prophylaxis.METHODS: From 2001 to October 2003, we studied GIB in 13 502 workers constructing the railroad on Mountain Tanggula which is 4905 m above the sea level. The incidence of GIB in workers at different altitudes was recorded. Endoscopy was performed when the workers evacuated to Golmud (2808 m) and Xining (2261 m). The available data on altitude GIB were analyzed.RESULTS: The overall incidence of GIB was 0.49% in 13 502 workers. The incidence increased with increasing altitude. The onset of symptoms in most patients was within three weeks after arrival at high altitude. Bleeding manifested as hematemesis, melaena or hematochezia, and might be occult. Endoscopic examination showed that the causes of altitude GIB included hemorrhage gastritis, gastric ulcer, duodenal ulcer, and gastric erosion. Experimental studies suggested that acute gastric mucosal lesion (AGML) could be induced by hypoxic and cold stress, which might be the pathogenesis of altitude GIB. Those who consumed large amount of alcohol, aspirin or dexamethasone were at a higher risk of developing GIB. Persons who previously suffered from peptic ulcer or high-altitude polycythemia were also at risk of developing GIB. Early diagnosis, evacuation, and treatment led to early recovery. CONCLUSION: GIB is a potentially life threatening disease, if it is not treated promptly and effectively. Early diagnosis, treatment and evacuation lead to an early recovery. Death due to altitude GIB can be avoided if early symptoms and signs are recognized.

Predicting an Athlete’s Physiological and Haematological Response to Live High-Train High Altitude Training Using a Hypoxic Sensitivity Test

Purpose Elite endurance runners frequently utilise live high-train high(LHTH)altitude training to improve endurance per-formance at sea level(SL).Individual variability in response to the hypoxic exposure have resulted in contradictory findings.In the present case study,changes in total haemoglobin mass(tHbmass)and physiological capacity,in response to 4-weeks of LHTH were documented.We tested if a hypoxic sensitivity test(HST)could predict altitude-induced adaptations to LHTH.Methods Fifteen elite athletes were selected to complete 4-weeks of LHTH(~2400 m).Athletes visited the laboratory for preliminary testing(PRE),to determine lactate threshold(LT),lactate turn point(LTP),maximal oxygen uptake VO_(2max)and tHbmass.During LHTH,athletes completed daily physiological measures[arterial oxygen saturation(SpO2)and body mass]and subjective wellbeing questions.Testing was repeated,for those who completed the full camp,post-LHTH(POST).Additionally,athletes completed the HST prior to LHTH.Results A difference(P<0.05)was found from PRE to POST in average tHbmass(1.8%±3.4%),VO_(2max)(2.7%±3.4%),LT(6.1%±4.6%)and LTP(5.4%±3.8%),after 4-weeks LHTH.HST revealed a decrease in oxygen saturation at rest(ΔSp_(r))and higher hypoxic ventilatory response at rest(HVRr)predicted individual changes tHbmass.Lower hypoxic cardiac response at rest(HCRr)and higher HVRr predicted individual changes VO_(2max).Conclusion Four weeks of LHTH at~2400 m increased tHbmass and enhanced physiological capacity in elite endurance runners.There was no observed relationship between these changes and baseline characteristics,pre-LHTH serum ferritin levels,or reported incidents of musculoskeletal injury or illness.The HST did however,estimate changes in tHbmass and VO_(2max).HST prior to LHTH could allow coaches and practitioners to better inform the acclimatisation strategies and train-ing load application of endurance runners at altitude.

Is Hypoxic/Altitude Training an Important Topic in the Field of Hypoxia?

Hypoxia is an essential topic in medical or biological sciences.The main aims of the present study were to examine the most important medical articles(i.e.,the top 100 most cited)on hypoxia.We examine how the Nobel-prize awarded hypoxia inducible factor(HIF)-pathway discovery in the early 1990s has changed the thematic composition of this body of literature,with a special emphasis on the studies linking hypoxia and cancer.We searched Pubmed for articles with the terms#Hypox,#Altitude,or#Mountain in the title that have been published in biomedical journals and ranked the articles on their number of citations in Web of Science.A second search was performed in all journals for articles related to hypoxia and cancer.Strikingly,only 12 of the top-100 most-cited articles on hypoxia and only 3 articles of the top-100 articles related to cancer were published before 1995.Moreover,only 5 articles from prior 1995 reached 1000 citations,while 27 articles published in 1995 or later were cited more than 1000 times,most of them on the HIF-1 pathway.Eighty percent of the top-100 articles were related to the HIF pathway,while there were no articles on the application of hypoxia either for therapeutic use(i.e.,hypoxic conditioning in patients)or for performance enhancement(i.e.,altitude training in athletes).In conclusion,the early-1990s discovery of the HIF pathway and of its molecular regulation has shifted the focus of hypoxia research towards molecular mechanisms and consequences of tissue hypoxia,most notably in cancer.The importance of studies focusing on clinical and performance applications of systemic hypoxia is relatively lower.

Effects of gangliosides combined with family rehabilitation training on nerve injury, neurodevelopment and oxidative stress in children with HIE

Objective:To study the effects of gangliosides combined with family rehabilitation training on nerve injury, neurodevelopment and oxidative stress in children with HIE.Methods:Children with HIE who were treated in Zigong Third People's Hospital between March 2015 and October 2017 were selected and randomly divided into two groups, rehabilitation training group received gangliosides combined with family rehabilitation training and negative control group accepted gangliosides combined with conventional rehabilitation intervention. The contents of nerve injury molecules, neurotrophic molecules and oxidative stress molecules in serum were measured before intervention and 3 months after intervention.Results: Compared with those of same group before intervention, serum VILIP1, NSE, UCH-L1, TNF-α, IL-6, NO, DM and MDA levels of both groups of children were significantly lower whereas BDNF, TRKB, NTF, NGF, SOD and GSH-PX levels were significantly higher 3 months after intervention, and serum VILIP1, NSE, UCH-L1, TNF-α, IL-6, NO, DM and MDA levels of rehabilitation training group after intervention were lower than those of negative control group whereas BDNF, TRKB, NTF, NGF, SOD and GSH-PX levels were higher than those of negative control group.Conclusion: Gangliosides combined with family rehabilitation training can reduce the nerve injury, improve the neurodevelopment and inhibit the oxidative stress in children with HIE.

Environmental enrichment promotes neural remodeling in newborn rats with hypoxic-ischemic brain damage

We evaluated the effect of hypoxic-ischemic brain damage and treatment with early environmental enrichment intervention on development of newborn rats, as evaluated by light and electron microscopy and morphometry. Early intervention with environmental enrichment intelligence training attenuated brain edema and neuronal injury, promoted neuronal repair, and increased neuronal plasticity in the frontal lobe cortex of the newborn rats with hypoxic-ischemic brain damage.

Non-enzymatic antioxidant blood plasma profile in the period of high training loads of elite speed skaters in the altitude

At the altitude,hypoxia and training load are key factors in the development of oxidative stress.Altitude-induced oxidative stress is developed due to the depletion of antioxidant potential.In the current study,we examined the non-enzymatic antioxidant profile of blood plasma in 7 males and 5 females specializing in speed skating at a 21-day training camp at 1850m above sea level.Training included:cycling,roller skating,ice skating,strength training,and special training.At the start point and the endpoint,total hemoglobin mass(tHb-mass),hemoglobin concentration,and circulating blood volume were determined.Antioxidant profiles,hypoxic doses,hypoxic impulses,and training impulses were assessed at 3,6,10,14,and 18 days.Antioxidant profiles consisting of“urate”and“thiol”parts were registered with chemiluminometry.In the training dynamics,antioxidant parameters changed individually,but in total there was a decrease in the“urate”capacity by a factor of 1.6(p=0.001)and an increase in the“thiol”capacity by a factor of 1.8(p=0.013).The changes in“urate”capacity positively correlated(r_(S)=0.40)and the changes in“thiol”capacity negatively correlated(r_(S)=−0.45)with changes in tHb-mass.Both exercise and hypoxic factors affect the antioxidant parameters bidirectionally.They correlated with a decrease in thiol capacity and with an increase in urate capacity.The assessment of the non-enzymatic antioxidant profile can be a simple and useful addition to screening the reactive oxygen species homeostasis and can help choose the personalized training schedule,individualize recovery and ergogenic support.

高水平竞走运动员大赛前高原训练负荷安排及效果分析

目的:探讨高原环境下高水平竞走运动员备战大赛前的训练负荷特征及其对竞技能力的影响。方法:以备战2023年成都世界大学生运动会及全国竞走冠军赛(日照站)的六名获奖运动员为研究对象,分析其在三个不同海拔高原训练的训练负荷安排特征及其竞技能力的变化。结果:(1)大赛前3次高原训练期间的有氧-混氧-高强度课的占比分别为,会泽:40%-40%-20%(男子运动员)和45%-30%-25%(女子运动员);太白:33%-33%-33%(男子运动员)和40%-37%-23%(女子运动员);榆中:30%-40%-30%(男子运动员)和35%-45%-20%(女子运动员);(2)大赛前3次高原训练后有氧、混氧、高强度训练的配速均提高,男运动员分别提高11s、6s、3s;女运动员分别提高17s、9s、2s;(3)大赛前3次高原训练后最大摄氧量相对值显著提升,3.14%~6.76%(男子运动员)和3.19%~9.58%(女子运动员);(4)VO2max的提升有助于运动员运动成绩的提高。结论:赛前高原训练需要针对高原海拔、运动员性别、训练阶段、训练任务等具体情况,动态划分强度区间,合理选择负荷模式,安排赛前减量调整,可有效提高竞走运动员的竞技能力和比赛成绩。

海拔对隧道内列车火灾烟气蔓延特性影响

为探究海拔高度对隧道内列车火灾烟气蔓延的影响,基于已被验证的数值模拟方法,结合三维非定常N-S方程和RNG k-ε湍流模型,采用滑移网格技术模拟了在隧道内匀速运行的列车发生火灾后减速并最终停在隧道内的整个运动过程,并利用动模型试验和缩尺隧道火灾试验数据验证了数值模拟方法的可靠性.结果表明:海拔高度对隧道内列车停车以后的火灾烟气蔓延影响明显;与低海拔隧道相比,同一时刻高海拔隧道拱顶同一位置处的烟气流速更快,烟气逆流至火源上游50 m处的时刻更早;车体周围温度分布也随着海拔高度的不断增加而呈现出逐渐上升的趋势.与0 m海拔隧道相比,5000 m海拔隧道内烟气逆流至火源上游50 m的时刻提前了102 s,同时列车停车360 s时隧道拱顶处的温度峰值增加了216 K,增幅达到42.9%.

海拔对隧道救援站列车火灾烟气蔓延特性的影响

采用三维非定常N-S方程和完全浮力修正的RNG k-ε湍流模型,基于滑移网格技术实现列车在隧道内的运动过程模拟,构建高海拔隧道紧急救援站列车火灾数值模拟方法,并利用现有动模型试验和隧道静止火灾试验数据验证数值模拟方法的可靠性和正确性,研究海拔对事故隧道、紧急救援站和列车中部车厢附近横通道内的烟气流速和温度分布的影响规律。研究结果表明:当着火列车驶入隧道紧急救援站时,活塞风主导了火灾烟气的蔓延趋势;在列车停车瞬间,随着海拔增大,事故隧道拱顶处和列车中部车厢附近横通道拱顶处的烟气流速峰值及温度峰值逐渐增大;列车停车后,活塞风逐渐衰减,烟气开始在隧道拱顶处向火源上游逆流;随着海拔增大,紧急救援站下游高温区域蔓延范围逐渐扩大,事故隧道拱顶处温度峰值随之升高;随着时间推移,高海拔与低海拔隧道拱顶处的温度峰值差异逐渐增大,可能对更高海拔隧道救援站内的人员安全造成更大的威胁;不同海拔处列车中部车厢附近横通道内人眼高度处的温度均超过330 K(对人体有危害),且在同一时刻,海拔越高,横通道内高温烟气层高度越低,烟气沉降速度明显加快。

脱离低压低氧环境对高原肺动脉高压大鼠肺血管重建和TNF-α表达的影响

目的 探究脱离低压低氧环境对高原肺动脉高压大鼠肺血管重建和肿瘤坏死因子-α(TNF-α)表达的影响。方法 取120只Wistar大鼠随机分为对照组、高海拔组(10、20、30天)、低海拔组(10、20、30、90天)。测定各组肺动脉压力和右心室肥厚指标,采用HE染色观察大鼠肺组织病理变化,评估肺血管重建程度[肺小动脉管壁厚度/外径百分比(WT%)和管壁面积/总面积百分比(WA%)],免疫组化法检测肺组织切片中TNF-α的表达。结果 与对照组比较,高海拔组大鼠平均肺动脉压(mPAP)、右心室肥厚指数(RVHI)、WT%、WA%、肺组织TNF-α表达均升高;与高海拔30天组比较,低海拔组大鼠mPAP、RVHI、WT%、WA%、肺组织TNF-α表达均降低;且随时间延长,变化更为显著(P<0.05)。随造模时间延长,肺血管管壁厚度呈逐步增厚,管腔逐步变小;以高海拔地区造模30天为低海拔组参考,随着返低海拔地区时间延长,肺血管管壁厚度呈逐步变薄,管腔逐步变大。结论 脱离低压低氧环境后,高原肺动脉高压大鼠右心室肥厚和肺血管重建改善,肺组织TNF-α表达降低。

袋鼠式护理联合被动康复训练在新生儿缺氧缺血性脑病中的应用

目的:探究袋鼠式护理(Kangaroo mother care,KMC)联合被动康复训练在新生儿缺氧缺血性脑病(Hypoxieischemic encephalopathy,HIE)患儿中的应用效果。方法:选取2020年3月至2021年12月于我院就诊的80例HIE患儿作为研究对象。按随机数字表法分为对照组和观察组,每组各40例。对照组采取常规护理联合被动康复训练,观察组采取KMC联合被动康复训练。分析比较两组的神经行为、神经系统后遗症发生率以及护理满意度。结果:护理后,两组的新生儿神经行为测定量表(Neonatal Behavioral Assessment Scale,NBNA)评分均高于护理前;并且观察组高于对照组(P<0.05)。观察组神经系统后遗症总发生率低于对照组(P<0.05)。观察组患儿家长满意度高于对照组(P<0.05)。结论:KMC联合被动康复训练可改善HIE患儿的神经行为,降低神经系统后遗症发生率,提高患儿家长的满意度。

急性缺氧暴露对人体生理反应及认知能力的影响研究

在低压环境舱开展高海拔环境中人体急性缺氧暴露实验,研究环境压力和温度对人体生理参数和认知能力的影响规律。实验结果表明,随大气压力的降低,人体平均皮肤温度、口腔温度、舒张压、心率和心率变异性均呈增加,而血氧饱和度和收缩压呈降低趋势。其中,平均皮肤温度、心率和血氧饱和度具有显著性差异(p<0.05)。随温度的增加,只有血氧饱和度降低,其他生理参数均升高。其中,平均皮肤温度、心率具有显著性差异(p<0.05)。感知能力、记忆能力和反应能力随大气压力的降低而降低,思辨能力反而提高。其中,记忆能力受压力影响具有显著性(p<0.05)。感知能力和记忆能力随温度的增加有所提高,思辨能力在不同压力下随温度的变化规律不同,反应能力随温度的降低而提高。其中反应能力受温度影响具有显著性(p<0.05)。该研究为保障平原地区人员急进高海拔地区生命健康安全提供有力支撑。

新质生产力视角下航空运输研究生高质量培养路径探究

航空运输研究生培养高质量发展是加快形成低空经济等新质生产力的重要基础。面对新一轮产业革命和科技革命向航空运输产业的渗透,航空运输研究生培养面临着专业博士学位结构不完善、跨学科交叉融合培养不充分、产教融合科教融汇不深入等诸多现实的困境,无法响应国家战略发展的现实需求。为此,高校需要构建跨学科人才培养体系,打破学科专业壁垒,升级多学科交叉培养;优化教学体系,紧密对接行业技术前沿,建设教学案例库;建立综合校企实践教研平台,依托产业有力支撑,优化多主体协同机制,提升航空运输高层次人才的培养能力,为加快促进新质生产力提供强劲动能。

坡度对铁路隧道救援站火灾烟气蔓延特性影响研究

为研究高海拔地区不同坡度条件下隧道紧急救援站火灾烟气蔓延特性,采用Fluent软件建立高海拔坡度铁路隧道紧急救援站列车火灾模型,通过分析救援站内烟气流速、温度等特征参数变化规律,探讨坡度变化对隧道救援站火灾烟气蔓延的影响。研究结果表明:列车停车时刻,随着隧道坡度由0‰变化至±30‰,隧道拱顶烟气流速峰值均逐渐减小。列车停车后,正坡度越大,烟气逆流流速峰值下降,烟气逆流长度越短;负坡度则与之相反。对于正坡度隧道,建议人员向火源的上游方向疏散逃生更安全;对于负坡度隧道而言,建议人员向火源的下游方向疏散逃生更安全。研究结果对高海拔隧道火灾防排烟系统设计以及人员疏散具有重要意义。

8周高原训练对赛艇运动员红细胞生成、铁代谢和有氧运动能力的影响

以28名男子赛艇运动员作为研究对象,分为高原组和平原组,旨在探讨持续8周的高原训练对男子赛艇运动员红细胞生成、铁代谢和有氧运动能力的影响.8周训练期间两组运动员均执行相同的训练计划,训练负荷基本保持一致.分别测量8周训练前后的最大摄氧量(VO_(2peak))和循环血红细胞计数(RBC)、网织红细胞(RET)%、血红蛋白(Hgb)浓度等红细胞参数,以及红铁酮(ERFE)、铁蛋白(FER)、可溶性转铁蛋白受体(sTfR)水平.研究结果发现:①与训练前相比,8周训练后高原组的VO_(2peak)、RVO_(2peak)(相对体重最大摄氧量)显著升高,平原组均无显著变化,两组间VO_(2peak)、RVO_(2peak)的变化均存在显著差异(+9.41%vs+3.03%,p<0.05;+12.83%vs+0.80%,p<0.01).②8周训练后,高原组的RBC、Hgb、HCT(红细胞压积)均显著升高,平原组略微下降.两组间Hgb、HCT的变化存在显著差异(+4.95%vs–3.21%,p<0.01;+6.48%vs–1.57%,p<0.01),RBC存在显著差异的趋势(+3.19%vs–3.61%,p=0.061);高原组和平原组的RET%、RET-He(网织红细胞血红蛋白含量)均未发生显著改变;但高原组的LFR(低荧光强度网织红细胞)、RPI(网织红细胞生成指数)显著升高,MFR(中荧光强度网织红细胞)、IRF(幼稚网织红细胞比率)均显著下降;两组间RPI的变化存在显著差异(+30.60%vs–4.52%,p<0.05).③8周训练后,高原组的FER显著下降,sTfR、sTfR/lg(FER)显著升高,ERFE无显著变化;平原组的ERFE显著升高,FER、sTfR、sTfR/lg(FER)均未发生显著改变;两组间FER、ERFE、sTfR、sTfR/lg(FER)的变化存在显著差异(+17.99%vs+121.31%,p<0.05;–36.16%vs–2.96%,p<0.05;+82.77%vs–8.87%,p<0.05;+108.40%vs–6.96%,p<0.05).④8周训练后,VO_(2peak)的变化幅度仅与循环血sTfR、sTfR/lg(FER)的变化幅度呈显著正相关.由此得出结论:持续8周的高原训练有助于提高赛艇运动员有氧运动能力和循环血的氧转运能力.8周高原训练后期,红细胞生物合成依然较为活跃.sTfR在有氧能力的改善中可能发挥着重要作用.