Changes in oxygen saturation in football players over 16 days at altitude in Quito, Ecuador (2,683 m).
DOI:
https://doi.org/10.11606/issn.1981-4690.2026e40242686Keywords:
Altitude, Football, Oxygen saturation, Heart rateAbstract
Football played at high altitudes exposes athletes to environmental hypoxia, which can reduce oxygen saturation and impair physical performance. Understanding the initial physiological responses and the progression of acclimatization is essential for planning training and competitions. The aim of this study was to evaluate changes in peripheral oxygen saturation (SaO2) and heart rate (HR) in under-20 football players native to low altitude during 16 days of exposure to 2,683 meters in Quito, Ecuador. Twenty athletes from a Brazilian first-division club were assessed. Resting SaO2 and HR were measured at sea level (3 m) and on the 1st, 8th, and 16th days after arrival at altitude. A digital pulse oximeter was used, and descriptive statistics and paired t-tests were applied in planned comparisons between each altitude time point and baseline (p < 0.05). A significant decrease in SaO2 was observed, from 98.20 ± 1.05% at sea level to 94.65 ± 3.37% on day 1, with partial recovery to 95.50 ± 2.60% on day 8 and 95.67 ± 2.80% on day 16, without returning to baseline values. HR remained stable throughout the period, ranging from 74.80 ± 11.19 bpm to 74.95 ± 12.07 bpm, 76.55 ± 13.59 bpm, and 75.33 ± 10.09 bpm on the evaluated days. The results suggest that early acclimatization partially improves SaO2, but 16 days are not sufficient for full normalization. The stability of HR indicates that more pronounced autonomic adjustments tend to occur during exercise. It is concluded that the altitude of 2,683 meters causes a significant reduction in SaO2, with incomplete recovery within two weeks, reinforcing the need for proper acclimatization planning to preserve athletic performance.
Downloads
References
1. Buchheit M, Hammond K, Bourdon PC, Simpson BM, Garvican-Lewis LA, Schmidt WF, et al. Relative match intensities at high altitude in highly-trained young soccer players (ISA3600). J Sports Sci Med. 2015;14:98-102.
2. Bondi D, Bhandari S, Verratti V. Case studies in physiology: nocturnal cardiorespiratory adaptive differences between an Italian trekker and a Nepali guide. Physiol Rep. 2020;8(16):e14537.
3. Pham K, Parikh K, Heinrich EC. Hypoxia and inflammation: insights from high-altitude physiology. Front Physiol. 2021;12:676782.
4. Sarikaya M, Öğe B, Embiyaoğlu NM, Selçuk M, Çınar V, Öner S, et al. The acute effects of simulated hypoxic training at different altitudes on oxidative stress and muscle damage in elite long-distance runners. PeerJ. 2025;13:e19338.
5. Parati G, Agostoni P, Basnyat B, Bilo G, Brugger H, Coca A, et al. Clinical recommendations for high altitude exposure of individuals with pre-existing cardiovascular conditions: a joint statement by multiple European societies. Eur Heart J. 2018;39(17):1546-54.
6. Bloch KE, Buenzli JC, Latshang TD, Ulrich S. Sleep at high altitude: guesses and facts. J Appl Physiol. 2015;119:1466-80.
7. West JB. High-altitude medicine. Am J Respir Crit Care Med. 2012;186(12):1229-37.
8. Ekblom B. Applied physiology of soccer. Sports Med. 1986;3(1):50-60.
9. Clark SA, Bourdon PC, Schmidt W, Singh B, Cable G, Onus KJ, et al. The effect of acute simulated moderate altitude on power, performance and pacing strategies in well-trained cyclists. Eur J Appl Physiol. 2007;102(1):45-55.
10. Bärtsch P, Saltin B. General introduction to altitude adaptation and mountain sickness. Scand J Med Sci Sports. 2008;18(Suppl 1):1-10.
11. Ramchandani N, Kumar P, Praveen P, Hasija N, Soni R, Gautam M, et al. Review of athletic guidelines for high-altitude training and acclimatization. Int J Med Students. 2024;12(1):12-20.
12. Sawka MN, Young AJ, Rock PB, Lyons TP, Boushel R, Freund BJ, et al. Altitude acclimatization and blood volume: effects of training and/or exposure on hemoglobin mass. J Appl Physiol. 2000;88(4):u1451-7.
13. Fulco CS, Rock PB, Cymerman A. Physiological responses to high-altitude exposure. Curr Sports Med Rep. 2000;1(6):252-6.
14. Gore CJ, Clark SA, Saunders PU. Soccer activity profile of altitude versus sea-level natives during acclimatization to 3600 m (ISA3600). Br J Sports Med. 2013;47(Suppl 1):i80-5.
15. Levine BD, Stray-Gundersen J. Living high-training low: effect of moderate-altitude acclimatization with low-altitude training on performance. J Appl Physiol. 2005;96(1):51-63.
16. Burtscher M, Gatterer H, Szubski C, Pierantozzi E, Faulhaber M. Intermittent hypoxia and endurance training: a perspective for improving performance and health at sea level and in hypoxia. Front Physiol. 2018;9:846.
Downloads
Published
Issue
Section
License
Copyright (c) 2026 Brazilian journal of physical education and sport
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
Todo o conteúdo da revista, exceto onde está identificado, está licenciado sob uma Licença Creative Commons (CC-BY)
