Hipoksik Ortamda Egzersize Bağlı Fizyolojik Yanıtlar
Özet
Bu çalışmada, hipoksik ortamda egzersize bağlı fizyolojik yanıtlar, aklimatizasyon mekanizmaları ve irtifa antrenman modelleri bütüncül bir şekilde incelenmektedir. Yüksek irtifada barometrik basınç ile oksijen parsiyel basıncındaki düşüş; solunum, kardiyovasküler ve hematolojik sistemlerde belirgin adaptasyon süreçlerini başlatır. İlk günlerde gelişen aklimatizasyon döneminde pulmoner ventilasyon yükselir, artan eritropoetin (EPO) salgısıyla birlikte alyuvar sayısı, hemoglobin ve hematokrit değerlerinde kayda değer artışlar meydana gelir; ayrıca eritrositlerdeki 2-3 DPG artışı oksihemoglobin ayrışım eğrisini sağa kaydırarak dokulara oksijen sunumunu kolaylaştırır. Sporcuların deniz seviyesindeki dayanıklılık performansını geliştirmek amacıyla, genellikle alçak-orta irtifa ortamlarında (1.800-2.500 metre) yılda 2-4 kez gerçekleştirilen, en az iki haftalık kamplar ve "yüksekte yaşa, alçakta antrenman yap" yaklaşımı tavsiye edilmektedir. Buna karşın, aşırı veya uzamış hipoksiye maruz kalmanın kas dokusu ve protein sentezi üzerinde olumsuz etkiler doğurabileceği, hipobarik simülasyon odalarının ise uyku, beslenme ve mukozal bağışıklık (IgA) parametrelerini bozabileceği vurgulanmaktadır. Sonuç olarak, hipoksik koşullarda planlanan egzersizlerin şiddetini denetlemek için kalp atım hızı ve laktat eşiklerinin bireysel varyasyonlar dikkate alınarak hassasiyetle izlenmesi ve uygun zamanlamanın yapılması gerekmektedir.
In this study, physiological responses to exercise in a hypoxic environment, acclimatization mechanisms, and altitude training models are comprehensively examined. The decrease in barometric pressure and oxygen partial pressure at high altitudes triggers distinct adaptation processes across the respiratory, cardiovascular, and hematological systems. During the acclimatization phase developing in the initial days, pulmonary ventilation increases, and elevated erythropoietin (EPO) secretion leads to significant rises in red blood cell count, hemoglobin, and hematocrit levels; additionally, the increase of 2-3 DPG in erythrocytes shifts the oxyhemoglobin dissociation curve to the right, facilitating oxygen delivery to tissues. To improve athletes' endurance performance at sea level, camps lasting at least two weeks conducted 2-4 times a year in low-to-moderate altitude environments (1,800-2,500 meters) and "live high, train low" approaches are recommended. Conversely, exposure to severe or prolonged hypoxia can induce adverse effects on muscle tissue and protein synthesis, whereas hypobaric simulation chambers may impair sleep, nutrition, and mucosal immunity (IgA) parameters. Consequently, to control exercise intensity under hypoxic conditions, heart rate and lactate thresholds must be carefully monitored taking individual variations into account, alongside precise timing of training schedules.
Referanslar
Atış, S. (2004) Yüksek irtifalarda ortaya çıkan acil akciğer sorunları. Eurasian J Pulmonol, 6 (1), 40-43.
Bartsch, P. & Saltin, B. (2008) General introduction to altitude adaptation and mountain sickness. Scand J Med Sci Sports, 18 (1), 1-10.
Bonetti, D. L. & Hopkins, W. G. (2009). Sea-level exercise performance following adaptation to hypoxia: a meta-analysis. Sports Med, 39 (2), 107-27.
Cahan, C. Hoekje, P. L. & Goldwasser, E. (1990). Assessing the characteristics between lenght of hypoxic exposure and serum eryhtropoietin levels. Am J Physiol, 258 (4 Pt 2), R1016-21.
Chapman, R. F. Stray-Gundersen, J. & Levine, B. D. (1998). Individual variation in response to altitude training. J Appl Physiol, 85 (4), 1448-56.
Desplanehes, D. Hoppeler, H. & Tüscher, L. (1996). Muscle tissue adaptation of high-altitude natives to training in chronic hypoxia or acute normoxia. J Appl Physiol, 81 (5), 1946-51.
Friedmann, B. Frese, F. & Menold, E. (2005). Individual variation in the reduction of heart rate and performance at lactate thresholds in acute normobaric hypoxia. Int J Sports Med, 26 (7), 531-6.
Grassi, B. Marzorati, M. & Kayser, B. (1996). Peak blood lactate and blood lactate vs. workload during acclimatization to 5,050 m and in deacclimatization. J Appl Physiol, 80 (2), 685-92.
Hall, J. E. (2017). Tıbbi fizyoloji. Ankara: Ayrıntı Basım ve Yayın Matbaacılık.
Hoppeler, H. & Vogt, M. (2001). Hypoxia training for sea-level performance. Training high-living low. Adv Exp Med Biol, 502, 61-73.
Knaupp, W. Khilnani, S. & Sherwood, J. (1992). Erythropoietin response to acute normobaric hypoxia in humans. J Appl Physiol, 73 (3), 837-40.
Levine, B. D. & Stray-Gundersen, J. (1997). “Living high-training low”: effect of moderate-altitude acclimatization with low-altitude training on performance. J Appl Physiol, 83 (1), 102-12.
Mazzeo, R. S. (2005). Altitude, exercise and immune function. exerc. Immunol. Rev, 11, 6-16.
Metin, G. (2004). Yüksek rakımlarda egzersiz. Eurasian J Pulmonol, 6 (2), 89-97.
Mishra, K. P. Ganju, L. & Singh, S. B. (2015). Hypoxia modulates innate immune factors: a review. International Immunopharmacology, 28 (1), 425-428.
Robergs, R. A. & Roberts, S. O. (1997). Exercise in extreme environments, exercise physiology, exercise performance and clinical applications. St Louis Mosby, 26, 640-653.
Rosa-Neto, J. C. Lira, F. S. & de Mello, M. T. (2011). Importance of exercise immunology in health promotion. Amino Acids, 41 (5), 1165-72.
Santos, S. A. Lira, F. S. & Silva, E. T. (2019). Effect of moderate exercise under hypoxia on th1/th2 cytokine balance. The Clinical Respiratory Journal, 13 (9), 583-589.
Saunders, P. U. Pyne, D. B. & Gore, C. J. (2009). Endurance training at altitude. High Altitude Medıcıne & Biology, 10 (2), 135-148.
Schmitt, L. Fouillot, J. P. & Millet, G. P. (2008). Altitude, heart rate variability and aerobic capacities. Int J Sports Med, 29 (4), 300-6.
Stray-Gundersen, J. Chapman, R. F. & Levine, B. D. (2001). “Living high-training low” altitude training improves sea level performance in male and female elite runners. J Appl Physiol, 91 (3), 1113-20.
Terrados, N. Melichna, J. & Sylven, C. (1988). Effects of training at simulated altitude on performance and muscle metabolie capacity in competitive road cyclists. Eur J Appl Physiol Occup Physiol, 57 (2), 203-9.
Tiollier, E. Schmitt, L. & Burnat, P. (2005). Living high-training low altitude training: effects on mucosal immunity. Eur J Appl Physiol, 94 (3), 298-304.
Weatherwax, R. M. Richardson, T. B. & Beltz, N. M. (2016). Verification testing to confirm vo2max in altitude-residing, endurance-trained runner. Int J Sports Med, 37 (7), 525-30.
Wolfel, E. E. Groves, B. M. & Brooks, G. A. (1991). Oxygen transport during steady-state submaximal exercise in chronic hypoxia. J Appl Physiol, 70 (3), 1129-36.
Zhang, H. Dong, H. & Mehmood, K. (2018). Physiological variations among blood parameters of domestic cats at high-and low-altitude regions of china. Archives of Physiology and Biochemistry, 124 (5), 458-460.
