Specifics of ventilatory and heart rate chemosensitivity related to special endurance capacity in high performance alpinists and endurance athletes
The aim was to compare ventilatory and heart rate chemosensitivity to hypoxia and hypercapnia in homogenous groups of high performance alpinists and endurance athletes and its relation to special work endurance.Thirty-two male best national alpinists (30.7±2.7 yrs, VO2max 63.7±1.9 ml. kg-1,min-1, 14.3±2.4 yrs of experience) and 24 high performance male road cyclists of national team (25.7±1.1 yrs, VO2max 74.5±1.5 ml.kg-1,min-1, 11.2±1.4 yrs of experience) were examined by isocapnic progressive hypoxia and CO2 rebreathing tests. Maximal oxygen uptake, lung ventilation and heart rate peak responses were measured in an incremental ergometric test at sea level. Special work capacity of 23 alpinists was evaluated as the best time of non complicated mountain climbing between the point at 3,290 and 4,300 m above the sea level. Special work capacity of cyclists was evaluated as the best time of the individual 50 km race at the sea level.The results showed no significant differences of the hypoxic ventilatory response in groups of alpinists and cyclists (p<0.05) But circulatory response evaluated by response of HR increase in answer to a decrease in O2 arterial blood saturation (SaO2) in alpinists was lower (p<0.05). Results showed that the evaluation of ventilatory and heart rate chemosensitivity in addition to measure of aerobic power may give important information for prevision of specific working capacity of high performance alpinists. Maximal oxygen uptake (ml/kg body mass) of the four best alpinists did not differ from the values of other alpinists. Special work capacity of alpinists was significantly related to tidal volume increase for the hypoxia test (r=-0.60) and to CO2 sensitivity (r=-0.67).The long-term exposure to environmental hypoxia and hypocapnia in alpinists generates specific changes in respiratory control. To evaluate special work capacity potential possibilities in a homogenous group of high performance alpinists first of all heart rate response sensitivity to hypoxia as well ventilatory response sensitivity to CO2had to be taken into account, but only an alpinist's aerobic power.
- 1. Forster HV, Pan LG. Breathing during exercise: demands, regulation, limitations (review). Adv Exp Med Biol 1988;227:257-326.
- 2. Mishchenko V. Cardiorespiratory reactivity and adaptation of athletes. Kiev: Scientific world; 2007.
- 3. Mines AH, Respiratory physiology. New York: Raven Press; 1993.
- 4. Dahan A, Nieuwenhuijs D, Teppema. Plasticity of central chemoreceptors: effect of bilateral carotid body resection in central cO2 sensivity. PloS Med 2007 Jul 24;4(7):239.
- 5. di Prampero PE. Factors limiting maximal performance in human. Eur J Appl Physiol 2003;90(3):420- 429.
- 6. Mishchenko VS, Bulatova MM. Effect of endurance physical training on cardio-respiratory system reactive features (mechanisms of training load accumulation influence). J Sports Med Phys Fitness 1993;33(2):95-106.
- 7. Donoghhue S, Fatemian M, Balanos GM, et al. Ventilatory acclimatization in response to very small changes in PO2 in humans. J Appl Physiol 2005 May;98(5):1587-1591.
- 8. Tomiak T, Lysenko E, Zasada M. Fast kinetics and sensitivity of cardiorespiratory responses in athletes of different sport events. Research Yearbook 2005;11:25-29.
- 9. Rebuck AS. Measurement of ventilatory response to CO2 by rebreathing. Chest 1976;70:118.
- 10. Chua TP, Coats AJ. The reproducibility and comparability of tests of the peripheral chemoreflex: comparing the transient hypoxic ventilatory drive test and the single-breath carbon dioxide response test in healthy subjects. Eur J Clin Invest 1995;25(12):887-892.
- 11. Kara T, Narkiewicz K, Somers VK. Chemoreflexes - physiology and clinical implications. Acta Physiol Scand 2003;177(3):377-384.
- 12. Kato T, Tsukanaka A, Harada T, Kosaka M, Matsui N. Effect on hypercapnia on changes in blood pH, plasma lactate and ammonia due to exercise. Eur J Appl Physiol 2005;95(5-6):400-408.
- 13. Dwinell MR, Janssen PL, Pizarro J, Bisgard GE. Effects of carotid body hypocapnia during ventilatory acclimatization to hypoxia. J Appl Physiol 1997 Jan;82(1):118-124
- 14. Collier DJ, Nickol aH, Milledge JS, van Ruiten HJ, Collier CJ, Swenson ER, Datta A, Wolff CB. Alveolar PCO2 oscillations and ventilation at sea level and at high altitude. J Appl Physiol 2008 Feb;104(2):404- 415.
- 15. Mateika JH, Mendello C, Obeid, Badr MS. Peripheral chemoreflex responsiveness is increased at elevated levels of carbon dioxide after episodic hypoxia in awake humans. J Appl Physiol 2004 Mar;96(3):1197-2205.
- 16. Chicharro JL, Hoyos J, Lucia A. Effects of endurance training on the isocapnic buffering and hypocapnic hyperventilation phases in professional-cyclists. Brit J Sports Med 2000; 34:450-455.
- 17. Ohyabu Y, Usami A, Ohyabu I, Ishida Y, Miyagawa C, Arai T, Honda Y. Ventilatory and heart rate chemosensitivity in track-and-field athletes. Eur J Appl Physiol Occup Physiol 1990;59(6):460-464.
- 18. Steinback CD, Salzer D, Medeiros PJ, Kowalchuk J, Shoemaker JK. Hypercapnic vs. hypoxic control of cardiovascular, cardiovagal, and sympathetic function. Am J Physiol Regul Integr Comp Physiol 2009;296(2):402-410.
- 19. Spyer KM, Dale N, Gourine AV. ATP is a key mediator of central and peripheral chemosensory transduction. Exp Physiol 2004 Jan;89(1):53-59.
- 20. Wood HE, Fatemian M, Robbins PA. Prior sustained hypoxia attenuates interaction between hypoxia and exercise as ventilatory stimuli in humans. Exp Physiol2007 Jan;92(1):273-286.