INFLUENCIA DE LA VARIACIÓN DE LA ALTITUD EN EL RENDIMIENTO ATLÉTICO DE LOS CORREDORES DE LARGA DISTANCIA

rbme Revista Brasileira de Medicina do Esporte Rev Bras Med Esporte 1517-8692 1806-9940 Sociedade Brasileira de Medicina do Exercício e do Esporte RESUMEN Introducción: La comunidad académica ha demostrado la relación del rendimiento deportivo en el atletismo con los principales factores del entrenamiento deportivo, incluida la psicología de la competición. En investigaciones recientes, se ha descubierto que el nivel de rendimiento deportivo también está relacionado con la altitud, el clima, el entorno del lugar y el horario de la competición. Hasta la fecha, no existen estudios que proporcionen una experiencia de formación teórica y práctica en el entorno regional de Ganzhou. Objetivo: Este trabajo analiza la influencia del entrenamiento en altitud en el rendimiento de los atletas profesionales de atletismo. Al mismo tiempo, analizamos los indicadores fisiológicos y bioquímicos de los atletas. Métodos: Varios corredores de larga distancia se sometieron a un entrenamiento en altitud de 8 semanas. Analizamos los indicadores fisiológicos y bioquímicos de los atletas antes y después del entrenamiento. Al mismo tiempo, realice un análisis matemático-estadístico sobre el rendimiento de los corredores de fondo antes y después del entrenamiento. Resultados: Tras el entrenamiento en altitud, la hemoglobina y los glóbulos rojos mostraron un descenso significativo (P<0,01). Tras el entrenamiento, el rendimiento de los atletas mejoró considerablemente (P<0,01). Conclusión: El entrenamiento en diferentes altitudes puede promover una curva ascendente en el rendimiento de los atletas hasta su meseta, en la cuarta semana de entrenamiento. Nivel de evidencia II; Estudios terapéuticos - Investigación de resultados. INTRODUCTION Improving the endurance and impressive speed of the middle and long-distance track and field athletes is the key means for China to prepare for the Olympic Games effectively. More athletes from high-altitude areas are engaged in such events.1 Traditional altitude training refers to organizing athletes to areas with suitable altitudes for regular special sports training. Athletes train at higher altitudes. They live in lower elevations. This can effectively overcome the disadvantage that the traditional altitude training exercise load cannot be maintained. The article analyzes why long-distance runners have achieved excellent results in a plateau environment. At the same time, we asked athletes to perform a blood test and performance analysis after altitude training. The research purpose of the article is to summarize the experience to improve the athletic level of long-distance runners better. Research objects and methods Research object We select 10 female middle and long-distance runners from the national team. Age 18.35±3.21 years old.2 All subjects are non-native people living on the plateau. They have not participated in altitude training and volunteered to participate in this experimental study. Research methods We let 10 outstanding female middle and long-distance running athletes who do not live in the plateau have traditional altitude training and high-altitude living and low-altitude training, respectively.3 Compare the changes of blood indicators in the two training modes through self-control. ‚ 5-week altitude training in Gannan Plateau From June 3rd to July 7th, 2019, the athletes of our national middle and long-distance running team, which we established for half a year, will conduct a five-week plateau training at the Gannan Plateau Base.4 The purpose is to improve the athlete’s athletic ability through basics. The running distance during the first plateau week is 92.13±3.21km. This exercise focuses on low-intensity aerobic training. After 1 week, the total amount of training increased to 149.15±7.29km. This exercise was significantly higher than the exercise at the first plateau. Aerobic training accounted for 78.78%±8.29%. Mixed oxygen accounts for 21.80%±7.28%. The following 4 weeks fluctuate according to this total amount of training. The amount of exercise was higher than the first week (P<0.05, Table 1). On July 8th, he went down to the Wuchuanya Plateau Training Base in Inner Mongolia. Table 1 Altitude training and simulated HiLo training volume km/week. Altitude training Simulate HiLo Week 1 92.13±3.21 102.75±24.51 Week 2 149.15±7.29 89.70±17.16 Week 3 148.88±71.73 81.00±15.12 Week 4 148.55±9.74 Week 5 151.38±22.73 3-week high-altitude living and low-altitude training From October 29th to November 18th, 2019, 21-day high-altitude living and low-altitude training were carried out in the hypoxic laboratory. Living at a high altitude means living in a low-oxygen room equivalent to 2500m for more than 10 hours a day.5 Low altitude training is carried out under normoxia. The average weekly running distance was 87.09±6.79km (Table 1). We arrange for athletes to carry out cycling training with 80% V·O2max intensity for 40 minutes three times a week under a low oxygen environment of 2000-2500m. The purpose of this is to increase hypoxia stimulation. Blood image determination Take blood under fasting and peaceful state to determine blood indicators. The content includes red blood cell number (RBC), hemoglobin (Hb) content, red blood cell width (RDW), white blood cell number (WBC) and average red blood cell hemoglobin content (MCH=Hb/RBC), average red blood cell hemoglobin concentration (MCHC=Hb/Hct), etc. Optimization of starting image posture of long-distance runners b'fh represents the number of all pixels in the image. Ic (i, j) represents the image frame of the starting posture of the current long-distance runner. Ig (i, j) represents the reference frame. (s, t) represents the relative position of the pixel block in the current frame and the pixel block in the reference frame.6 Use formula (1) to express (1) E ′ w e r = ( s , t ) e ′ s g p i + I c ( i , j ) I g ( i , j ) * S ′ w e y + b ′ f h e'sgpi represents the direction of the final motion vector of the pixel block in the reference frame. (s*, t*) represents the vector direction of a pair of pixel blocks with the smallest absolute difference.7 Use formula (2) to give the reasonable matching threshold of the starting posture of long-distance runners (2) S ′ w e y = ( s * , t * ) × A ″ d g ′ s g ∓ d l o p Ád represents the absolute difference between the pixel block to be matched in the current frame and the pixel block at the same position in the reference frame. d'lop represents the number of starting positions of local athletes included in the window. s'sh represents the average motion energy of any target pixel. K'ser represents the average value of the motion energy of the background pixel block in each consecutive frame within T time.8 Use formula (3) to complete the optimization and correction of the starting posture of long-distance runners (3) q ′ s g = K ′ s e r ∓ T s ′ s h × E w e r S w e p Data processing SPSS11.0 statistically processes all data. One-way analysis of variance compares the changes of blood image indicators in different periods.9 The significance level is 0.05. RESULTS The number of athletes’ RBC, RDW, and WBC did not change much in the later stage of altitude training (the 5th week). Hb, MCH and MCHC were significantly reduced. The RDW increased significantly when the plateau was reached for 1 week, but the MCHC decreased significantly. At 2 weeks, Hb and MCHC decreased significantly, and RDW increased significantly. We compare the data before simulating high-altitude living and low-altitude training.10 After high-altitude living and low-altitude training, the blood indicators of athletes do not change significantly. Only two weeks after leaving the hypoxic chamber, the MCHC decreased significantly (Tables 2 and 3). Table 2 Changes in blood image indexes during plateau training in Gannan Plateau (n=8). RCB / 1012gL-1 Hb / gL-1 MCH / pg 4.36±1.23 45.63±6.68 33.44±2.16 In front of the plateau 1 week 4.33±1.24 143.11±5.93 33.16±1.96 Two weeks 4.29±1.24 144.38±11.82 33.66±1.96 3 weeks 4.59±1.21 139.51±3.59 31.48±1.64 4 weeks 4.44±1.13 132.51±9.32 29.86±1.61 Shimokogen 5 weeks 4.42±1.16 134.11±3.46 31.38±1.66 1 week 4.51±1.15 144.11±6.16 32.16±1.86 Two weeks 4.33±1.15 132.16±5.68 31.61±2.14 MCH / % RDW WBC / 109 ± L-1 396.16±8.16 11.11±1.53 4.64±1.26 In front of the plateau 1 week 391.11±11.62 1.46±1.56 5.83±1.94 Two weeks 392.85±6.41 11.61±1.63 4.59±1.88 3 weeks 346.91±6.11 13.61±1.11 5.68±1.91 4 weeks 345.84±5.85 11.16±1.91 4.44±1.98 Shimokogen 5 weeks 349.12±11.41 11.18±1.65 4.68±1.62 1 week 346.85±3.96 14.23±1.18 5.66±1.93 Two weeks 356.84±9.62 14.42±1.81 4.63±1.23 Table 3 Changes in blood image indexes during simulated high-altitude living and low-altitude training (n=8). RCB / 1012gL-1 Hb / gL-1 MCH / pg 4.44±4.31 44.13±11.87 34.45±1.44 In front of Hilo 1 week 4.35±4.34 146.38±7.67 33.78±1.36 Two weeks 4.51±4.45 154.54±7.47 33.44±1.65 After HiLo 3 weeks 4.44±4.41 45.44±8.86 34.68±1.54 Two weeks 4.55±4.38 41.44±11.14 31.46±1.77 MCH / % RDW WBC / 109 ± L-1 373.75±6.8838 3.21±2.45 6.65±1.43 In front of Hilo 1 week 1.22±8.21 12.81±2.32 7.35±1.48 Two weeks 396.39±12.62 12.99±2.59 9.24±1.22 After HiLo 3 weeks 376.39±4.2736 13.23±2.45 7.19±1.39 Two weeks 1.25±5.85 12.38±2.82 5.38±1.12 DISCUSSION In this experiment, RBC, Hb, MCH, and MCHC did not change during the first to third weeks of altitude training. High altitude hypoxia causes an increase in EPO secreted by the kidneys. EPO promotes the differentiation of bone marrow stem cells into primitive red blood cells to accelerate the evolution of primitive red blood cells into RBC. It can promote the rapid release of reticulocytes. RBC has enhanced oxygen-carrying capacity.11 In this study, the indexes of RBC, Hb, etc., did not increase during altitude training for 1 to 3 weeks because the experimental subjects were young athletes who participated in altitude training for the first time. Although the amount of exercise taken in the first week of the plateau is not large, the amount of exercise is still slightly larger for those players who have no experience in altitude training. Large exercise load causes increased physical consumption. This results in little difference between the rate of destruction and generation of blood cells. The body gradually adapts to altitude hypoxia in the first 2-3 weeks of altitude training, and the amount of exercise scheduled is significantly higher than that in the first week.12 The number of athletes’ RBC in the third week of altitude training was 5.1% higher than that before altitude. Hb is slightly reduced but not significant. It shows that the athlete has fully adapted to the hypoxic environment. It is quite controversial whether blood indicators such as RBC and Hb can be maintained at a high level after going down to the plateau. We consider many factors such as climate, training conditions, and gradual changes in altitude. After training on Gannan Plateau, the team arrived in Wuchuan, Inner Mongolia, located in the sub-plateau.13 In the first week after going down to the plateau, small and medium-intensity adjustment training was arranged. The overall training volume is small, so the Hb increases significantly in the first week after altitude training. This is the same as the highest level during the plateau period. The RBC level is also similar to the highest level during the plateau. MCH and MCHC are the same as those after altitude training. Sudden changes in the environment cause the neuroendocrine system to stimulate the kidneys to secrete EPO. However, the subsequent loss of altitude training effect and the alleviation of hypoxia will cause an increase in EPO secretion for a short period.14 Therefore, Hb decreased significantly in the second week from the plateau to the sub-plateau (P<0.05). Of course, we do not rule out that the low Hb in the second week of reaching the sub-plateau is related to the increased amount of exercise performed. This study used 3 weeks of HiLo training. Except for the obvious fluctuation of MCHC, other blood indicators changed a little before and after training.15 However, the indicators remain at a relatively high level. Two weeks after leaving the hypoxic chamber, Hb decreased somewhat but not significantly. Altitude training is a complicated issue. It involves the athlete’s training level, functional level, training environment, geographical location, natural conditions, and other internal factors. CONCLUSION The implementation of classic altitude training programs for elite female athletes without altitude training experience has not achieved the expected effect of improving the number of red blood cells and hemoglobin content. After the altitude training, the simulated HiLo training was performed for 21 days, and the RBC and Hb indexes did not change significantly. Simulated HiLo training RBC, Hb, and other indicators are always at a relatively high level, and the effect of HiLo training can last about 2 weeks. REFERENCES 1 Liu Y Hua S Jia R Huang J Effect of aerosols on the ice cloud properties over the Tibetan Plateau Journal of Geophysical Research: Atmospheres 2019 124 16 9594 9608 1 Liu Y, Hua S, Jia R, Huang J. Effect of aerosols on the ice cloud properties over the Tibetan Plateau. Journal of Geophysical Research: Atmospheres. 2019;124(16):9594-608. 2 Boccia G Cardinale M Brustio PR Performance progression of elite jumpers: Early performances do not predict later success Scandinavian Journal of Medicine & Science in Sports 2021 31 1 132 139 2 Boccia G, Cardinale M, Brustio PR. Performance progression of elite jumpers: Early performances do not predict later success. Scandinavian Journal of Medicine & Science in Sports. 2021;31(1):132-9. 3 Hadiyan H Cosh S Level of physical and motor fitness post retirement and maintenance of athletic identity within active retired athletes Journal of Loss and Trauma 2019 24 1 84 95 3 Hadiyan H, Cosh S. Level of physical and motor fitness post retirement and maintenance of athletic identity within active retired athletes. Journal of Loss and Trauma. 2019;24(1):84-95. 4 Snyder KA Evers L Chambers JC Dunham J Bradford JB Loik ME Effects of changing climate on the hydrological cycle in cold desert ecosystems of the Great Basin and Columbia Plateau Rangeland Ecology & Management 2019 72 1 1 12 4 Snyder KA, Evers L, Chambers JC, Dunham J, Bradford JB, Loik ME. Effects of changing climate on the hydrological cycle in cold desert ecosystems of the Great Basin and Columbia Plateau. Rangeland Ecology & Management. 2019;72(1):1-12. 5 Li H Li X Zhou X Trait means predict performance under water limitation better than plasticity for seedlings of Poaceae species on the eastern Tibetan Plateau Ecology and evolution 2020 10 6 2944 2955 5 Li H, Li X, Zhou X. Trait means predict performance under water limitation better than plasticity for seedlings of Poaceae species on the eastern Tibetan Plateau. Ecology and evolution. 2020;10(6):2944-55. 6 Mao X Wei X Engel B Wang W Jin X Jin Y Biological response to 5 years of operations of cascade rubber dams in a plateau urban river, China River Research and Applications 2021 37 8 1201 1211 6 Mao X, Wei X, Engel B, Wang W, Jin X, Jin Y. Biological response to 5 years of operations of cascade rubber dams in a plateau urban river, China. River Research and Applications. 2021;37(8):1201-11. 7 Wang DB Wang XY Wu Y Lin HL Grazing buffers the effect of climate change on the species diversity of seedlings in an alpine meadow on the Tibetan Plateau Ecology and evolution 2019 9 3 1119 1126 7 Wang DB, Wang XY, Wu Y, Lin HL. Grazing buffers the effect of climate change on the species diversity of seedlings in an alpine meadow on the Tibetan Plateau. Ecology and evolution. 2019;9(3):1119-26. 8 Uhey DA Hofstetter RW Remke M Vissa S Haubensak KA Climate and vegetation structure shape ant communities along elevational gradients on the Colorado Plateau Ecology and evolution 2020 10 15 8313 8322 8 Uhey DA, Hofstetter RW, Remke M, Vissa S, Haubensak KA. Climate and vegetation structure shape ant communities along elevational gradients on the Colorado Plateau. Ecology and evolution. 2020;10(15):8313-22. 9 Pan B Cai S Geng H Numerical simulation of landscape evolution and mountain uplift history constrain—A case study from the youthful stage mountains around the central Hexi Corridor, NE Tibetan Plateau Science China Earth Sciences 2021 64 3 412 424 9 Pan B, Cai S, Geng H. Numerical simulation of landscape evolution and mountain uplift history constrain—A case study from the youthful stage mountains around the central Hexi Corridor, NE Tibetan Plateau. Science China Earth Sciences. 2021;64(3):412-24. 10 Gu L O’Hara KL Li WZ Gong ZW Spatial patterns and interspecific associations among trees at different stand development stages in the natural secondary forests on the Loess Plateau, China Ecology and evolution 2019 9 11 6410 6421 10 Gu L, O’Hara KL, Li WZ, Gong ZW. Spatial patterns and interspecific associations among trees at different stand development stages in the natural secondary forests on the Loess Plateau, China. Ecology and evolution. 2019;9(11):6410-21. 11 Liu M Che Y Jiao J Li L Jiang X Exploring the community phylogenetic structure along the slope aspect of subalpine meadows in the eastern Qinghai–Tibetan Plateau, China Ecology and evolution 2019 9 9 5270 5280 11 Liu M, Che Y, Jiao J, Li L, Jiang X. Exploring the community phylogenetic structure along the slope aspect of subalpine meadows in the eastern Qinghai–Tibetan Plateau, China. Ecology and evolution. 2019;9(9):5270-80. 12 Zhao D Wu S Projected changes in permafrost active layer thickness over the Qinghai‐Tibet Plateau under climate change Water Resources Research 2019 55 9 7860 7875 12 Zhao D, Wu S. Projected changes in permafrost active layer thickness over the Qinghai‐Tibet Plateau under climate change. Water Resources Research. 2019;55(9):7860-75. 13 Bishop TB Munson S Gill RA Belnap J Petersen SL Clair SBS Spatiotemporal patterns of cheatgrass invasion in Colorado Plateau National Parks Landscape Ecology 2019 34 4 925 941 13 Bishop TB, Munson S, Gill RA, Belnap J, Petersen SL, Clair SBS. Spatiotemporal patterns of cheatgrass invasion in Colorado Plateau National Parks. Landscape Ecology. 2019;34(4):925-41. 14 Chai Q Ma Z An Q Wu GL Chang X Zheng J Does Caragana korshinskii plantation increase soil carbon continuously in a water-limited landscape on the Loess Plateau, China? Land Degradation & Development 2019 30 14 1691 1698 14 Chai Q, Ma Z, An Q, Wu GL, Chang X, Zheng J et al. Does Caragana korshinskii plantation increase soil carbon continuously in a water-limited landscape on the Loess Plateau, China?. Land Degradation & Development. 2019;30(14):1691-8. 15 Nan Y Tian L He Z Tian F Shao L The value of water isotope data on improving process understanding in a glacierized catchment on the Tibetan Plateau Hydrology and Earth System Sciences 2021 25 6 3653 3673 15 Nan Y, Tian L, He Z, Tian F, Shao L. The value of water isotope data on improving process understanding in a glacierized catchment on the Tibetan Plateau. Hydrology and Earth System Sciences. 2021;25(6):3653-73.