Dr.Med. V.P. Ganapolsky¹
PhD V.O. Matytsin¹
Dr.Med., Professor P.V. Rodichkin^2
1S.M. Kirov Military Medical Academy, St. Petersburg

Keywords: interval hypoxic training, altitude training, physical efficiency, athletes.

Background. Regular trainings are critical for competitive progress and success. Among other things, athletes compete not only in "domestic" competitions, but travel to areas with different climates and terrains. Thus, the Mexico City 1968 Olympic Games were held at the altitude of about 2300 m above sea level, which corresponds to the midland conditions. The reduced oxygen partial pressure contributes to the development of high-altitude hypoxia of varying severity, which depends on the individual hypoxia sensitivity, even in those physically fit.

At the same time, moderate hypoxia can spur the adaptation processes in the body resulting in the activation of the oxygen transport function and increased oxygen utilization by tissues. This mechanism is realized by increasing the production of the hypoxia-inducible factor (HIF-1), which regulates erythropoiesis, vascular growth and adaptation of the cells to hypoxia due to the changes in blood glucose utilization [1]. Therefore, various types of hypoxic training are used to increase the general adaptive reserves of the body of athletes [1, 2], as well as the rehabilitation of patients diagnosed with various chronic diseases [3].

Objective of the study was to rate benefits of interval hypoxic training model for physical progress in mountaineering sport tested by the maximal oxygen consumption and endurance tests.

Methods and structure of the study. Experiments under the study were designed to test 8-days-long daily interval hypoxic training on a sample of 15 male athletes using Tabay altitude chamber. A daily session included 8 altitude trainings, each taking a 10-15min ascend to reach the preset altitude, 1-hour stay there and a 10-15min descend at 10-15m/s. Prior to and after every training the athletes were tested by a cycle ergometer test with maximal oxygen consumption tests on the maximal-intensity peak. We used Ergoline Select cycle ergometer for the tests, with the workload stepped up by 50W from 0 to 250-350W. We also used MetaLyser (Germany-based Cortex made) metabolography system to obtain the hemodynamic, spirometric and ergometric test data.

The study involved 15 male athletes aged 23 to 30 years - members of the professional team of alpine climbers. The athletes’ body weight ranged from 63 to 85 kg; their body length - from 167 to 182 cm. During the entire testing, the athletes had three meals per day with a similar dietary structure. The study was approved by the local ethics committee and was conducted on the basis of FSBEI HE "S.M. Kirov Military Medical Academy" of the Ministry of Defense of the Russian Federation (Protocol No. 203 dated March 20, 2018); all athletes gave a written consent to participate in the study.

The interval hypoxic trainings were done on Tabay altitude chamber (Japan). A daily session included 8 altitude trainings, each taking a 10-15min ascend to reach the preset altitude, 1-hour stay there and a 10-15min descend at 10-15m/s. During the first ascend, the simulated altitude was 1500 m, during the second one - 2000 m, the subsequent ascends - 2500 m above sea level. The air temperature in the thermal bar complex ranged from 18-27 °C, the relative humidity was 20-30%. The chamber was periodically ventilated to remove the accumulated carbon dioxide. The hypoxic training was conducted under conditions of physical rest without loading.

Before the start of the interval hypoxic training course and after its completion, the participants performed a stepped cardiorespiratory system functionality test until they reached the anaerobic threshold. This loading test was carried out to assess possible changes in the athletes’ physical efficiency and endurance caused by the interval hypoxic trainings. We used Ergoline Select cycle ergometer for the tests, with the workload stepped up by 50W from 0 to 250-350W. We also used MetaLyser (Germany-based Cortex made) metabolography system to obtain the hemodynamic, spirometric and ergometric test data shown in detail in Table.

Results and discussion. After the interval hypoxic training course, the maximum oxygen consumption (MOC) rate at the peak of physical activity grew by 7% in the mountaineering sample (see Table). We also registered a statistically significant increase in the minute ventilation rate by 13%. The growth of the above indicators was noted in all 15 athletes.

Therefore, the increase in the athletes’ MOC rate after the interval hypoxic training course, modeling the altitude (2500 m above sea level) performance, indicates increased physical efficiency and endurance. At the same time, the increase in the minute ventilation rate can be one of the possible mechanisms ensuring the increase in oxygen consumption, as was suggested, due to the changes in the lower limb [4] and respiratory [5] muscles.

Table 1. Dynamics of cardiorespiratory parameters prior to and after training course

Note. * - significance of differences measured by the Wilcoxon test.

Conclusions. The findings indicate that interval hypoxic training can increase athletes’ maximal oxygen consumption rate at the peak of their physical activity, which testifies to the increase of their physical efficiency and endurance. Interval hypoxic training can be included in the athletic training system.

References

1. Viscor G. et al. Physiological and Biological Responses to Short-Term Intermittent Hypobaric Hypoxia Exposure: From Sports and Mountain Medicine to New Biomedical Applications. Front Physiol. 2018. Vol. 9. P. 814.
2. Levine B.D. Intermittent hypoxic training: fact and fancy. High Alt. Med. Biol. 2002. Vol. 3, no. 2. pp. 177–193.
3. Serebrovskaya T.V., Xi L. Intermittent hypoxia training as non-pharmacologic therapy for cardiovascular diseases: Practical analysis on methods and equipment. Exp. Biol. Med. (Maywood). 2016. Vol. 241, no. 15. P. 1708–1723.
4. Kon M. et al. Effects of systemic hypoxia on human muscular adaptations to resistance exercise training. Physiological Reports. 2014. Vol. 2, no. 6. P. e12033.
5. Vallier J.M., Chateau P., Guezennec C.Y. Effects of physical training in a hypobaric chamber on the physical performance of competitive triathletes. Eur J Appl Physiol Occup Physiol. 1996. Vol. 73, no. 5. P. 471–478.

Corresponding author: matitsin@list.ru

Abstract

Regular trainings are critical for competitive progress and success. Objective of the study was to rate benefits of interval hypoxic training model for physical progress in mountaineering sport tested by the maximal oxygen consumption and endurance tests. Experiments under the study were designed to test 8-days-long daily interval hypoxic training on a sample of 15 male athletes using Tabay altitude chamber. A daily session included 8 altitude trainings, each taking a 10-15min ascend to reach the preset altitude, 1-hour stay there and a 10-15min descend at 10-15m/s. Prior to and after every training the athletes were tested by a cycle ergometer test with maximal oxygen consumption tests on the maximal-intensity peak. We used Ergoline Select cycle ergometer for the tests, with the workload stepped up by 50W from 0 to 250-350W. We also used MetaLyser (Germany-based Cortex made) metabolography system to obtain the hemodynamic, spirometric and ergometric test data.

The interval hypoxic training to model altitude (2500m) performance for physical progress and endurance was found beneficial as verified by the maximal oxygen consumption growth by 7% in the mountaineering sample. This finding gives grounds to recommend the interval hypoxic training model for modern athletic training systems.