Microcirculatory Blood Flow in the Skin During Interval Normobaric Hypoxic Training as Measured by Laser Doppler Flowmetry

Introduction. Currently, there is convincing evidence on the clinical effectiveness of interval hypoxic training in a wide range of diseases; however, data on the response of the microcirculatory system are lacking.

Objective. To study the response of microcirculatory blood flow as measured by laser Doppler flowmetry in various areas of the skin during interval hypoxicnormoxic training (IHNT).

Materials and Methods. Microcirculation was assessed using portable laser Doppler flowmeters in the skin of the forehead, forearm and finger during IHNT in 9 young (25–35 years old) healthy volunteers. Each subject successively underwent 4 IHNT sessions, with the oxygen concentration in the inhaled air reduced by 1 % at each subsequent training session (14 %→13 %→12 %→11 %). Each IHNT session consisted of 5 cycles of 5/3 minutes (hypoxia/normoxia). The dynamics of the perfusion level and the amplitude of myogenic vasomotions, which reflect the degree of opening of precapillary sphincters, were evaluated.

Results. During IHNT, the reaction of skin microvessels to systemic hypoxia demonstrated pronounced regional features. In the skin of the forehead (structurally belonging to the internal carotid artery territory), an increase in the level of perfusion was noted (up to a 60 % increase during IHNT), with no changes in the amplitude of myogenic vasomotions. In the finger skin, where the shunt (thermoregulatory) type of perfusion predominates, the opposite reaction was noted: an increase in the amplitude of myogenic vasomotions (up to an 80 % increase during IHNT), with no changes in the perfusion level. In the skin of the forearm, where the nature of perfusion is predominantly nutritive, both the level of perfusion (up to a 120 % increase during IHNT) and the amplitude of myogenic vasomotions (up to a 90 % increase during IHNT) increased.

Conclusion. The results obtained demonstrate significant changes in the functional state of the resistive microvessels of the skin under systemic hypoxia; however, the reaction has clearly defined regional features.

1. Sergeeva EN, Avdeenko YG, Kiryanova VV, Naumenko MA. The use of clinical protocols and standarts of care of adult patients of neurological and orthopedictraumatological profile by a physiotherapist in the outpatient link (review). Physiotherapy, Balneology and Rehabilitation. 2022;21(1):5–18. (In Russ.)]. Doi: 10.17816/rjpbr109485.

2. Shi Y, Wu W. Multimodal non-invasive non-pharmacological therapies for chronic pain: mechanisms and progress. BMC Med. 2023;21:372. Doi: 10.1186/s12916-023-03076-2.

3. Mashanskaya AV, Pogodina AV, Atalyan AV, et al. Interval hypoxic training in rehabilitation program for adolescents with overweight. Obesity and comorbid arterial hypertension: open-label randomized study. Current Pediatrics. 2021;20(1):51–61. (In Russ.)]. Doi: 10.15690/vsp.v20i1.2236.

4. Geppe NA, Glazachev OS, Timofeev YuS, et al. Hypoxic conditioning in comprehensive rehabilitation of children with bronchial asthma after coronavirus infection. Clinical Practice in Pediatrics. 2021;16(4):7–15. (In Russ.)]. Doi: 10.20953/18177646-2021-4-7-15.

5. Glazachev OS, Lyamina NP, Spirina GK. Intermittent hypoxic conditioning: experience and potential in cardiac rehabilitation programs. Russian Journal of Cardiology. 2021;26(5):156–162. (In Russ.)]. Doi: 10.15829/15604071-2021-4426.

6. Ivanov AB, Borukaeva IKh, Abazova ZKh, et al. Intermittent hypoxic therapy in the treatment of bronchial asthma patients with various chronotypes. Ulyanovsk medico-biological journal. 2021;(2):125–135. (In Russ.)]. Doi: 10.34014/2227-18482021-2-125-135.

7. Misirova IA, Startseva SV, Borukaeva IKh, et al. Long-term data of interval hypoxic therapy in patients rehabilitation after COVID-19. Immunopathology, allergology, infectology. 2023;(1):87–92. (In Russ.)]. Doi: 10.14427/jipai.2023.1.87.

8. Borukaeva IK, Abazova ZK, Ivanov AB, et al. Effect of interval hypoxytherapy on the immune status of hypertensive patients. Russian Journal of Immunology. 2024;27(2):273–280. (In Russ.)]. Doi: 10.46235/1028-7221-16833-EOI.

9. Dhif I, Glazachev OS, Bestavashvili AA, et al. Intermittent hypoxic preconditioning reduces the risk of peri- and postoperative complications during on-pump cardiac surgery. Russian Journal of Cardiology. 2024;29(7):15–24. (In Russ.)]. Doi: 10.15829/1560-4071-2024-5778.

10. Zhang X, Achkasov EE, Dudnik EN, et al. Experience of hypoxic conditioning in rehabilitation programs for patients with chronic occupational lung diseases: a pilot study. Bulletin of Rehabilitation Medicine. 2025;24(3):18–28. (In Russ.)]. Doi: 10.38025/2078-1962-2025-24-3-18-28.

11. Ososkov VS, Fedorovich AA, Korolev AI, et al. Clinical effects of hypoxic interval training in patients with chronic non-infectious diseases (review). Regional blood circulation and microcirculation. 2025;24(4):4–11. (In Russ.)]. Doi: 10.24884/1682-66552025-24-4-4-11.

12. Tsyganova TN, Kulchitskaya DB. Effectiveness of interval hypoxic training in obstetrics and gynecology (brief literature report). Journal of New Medical Technologies. Electronic ed. 2017;(4). (In Russ.)]. Doi: 10.12737/article_5a16df3aea1bf5.78205373.

13. Bayer U, Likar R, Pinter G, et al. Effects of intermittent hypoxia-hyperoxia on mobility and perceived health in geriatric patients performing a multimodal training intervention: a randomized controlled trial. BMC Geriatr. 2019;19(1):167. Doi: 10.1186/s12877-019-1184-1.

14. Mikhalishchina AS, Zagayniy ED, Vasina YaV, Glazachev OS. Effect of single interval hypoxic stimulation on cognitive functions of healthy volunteers. Psychophysiology News. 2023;(4):86–95. (In Russ.)]. Doi: 10.34985/d26995404-1619-b.

15. Venerin AA, Nikonov DV, Glazachev OS. Stability of analytic-holistic cognitive style under simulated normobaric hypoxia. Human Physiology. 2025;51(6):33–44. (In Russ.)]. Doi: 10.7868/S3034615025060035.

16. Saurov EA, Morozov SN. The method of interval hypoxic training as a factor in increasing performance in underwater sports. International Research Journal. 2021;(4):110–114. (In Russ.)]. Doi: 10.23670/IRJ.2021.106.4.084.

17. Burtscher J, Glazachev OS, Kopp M, Burtscher M. Effects of intermittent hypoxia exposures and interval hypoxic training on exercise tolerance (narrative review). Sports Medicine: Research and Practice. 2024;14(2):16–23. Doi: 10.47529/2223-2524.2024.2.5.

18. Katuntsev VP, Baranov MV, Zakharov SYu, et al. Adaptation to intermittent hypoxia: influence on the state of endothelial function. Human Physiology. 2021;47(3):72–79. (In Russ.)]. Doi: 10.31857/S0131164621030061.

19. Bondarenko NN, Khomutov EV, Ryapolova TL, et al. Molecular and cellular mechanisms of hypoxic response. Ulyanovsk Medico-Biological Journal. 2023;(2): 6–29. (In Russ.)]. Doi: 10.34014/2227-1848-2023-2-6-29.

20. Semenova TN, Kashchevskaya VM. Physiological mechanisms of organism adaptation to interval hypoxic training: cardiorespiratory and metabolic response. Medicine. Sociology. Philosophy. Applied Research. 2025;(3):8–12. (In Russ.)]. eLIBRARY ID: 82630178.

21. Pugh CW, Ratcliffe PJ. New horizons in hypoxia signaling pathways. Experimental Cell Research. 2017;356(2):116– 121. Doi: 10.1016/j.yexcr.2017.03.008.

22. Hoppeler H, Vogt M. Muscle tissue adaptations to hypoxia. J Exp Biol. 2001;204(Pt 18):3133–3139. Doi: 10.1242/jeb.204.18.3133.

23. [Anisimova AV, Krupatkin AI, Sidorov VV, et al. Laser doppler flowmetry in the assessment of the microcirculation in patients with acute and chronic cerebrovascular insufficiency. Regional blood circulation and microcirculation. 2014;13(3):31–37. (In Russ.)]. eLIBRARY ID: 22808180.

24. Meerson F. Z., Pshennikova M. G. Adaptation to stressful situations and physical exertion. M.: Medicine; 1988. 256 p. (In Russ.)].

25. Krupatkin AI, Sidorov VV, Fedorovich AA, et al. Regional blood circulation and microcirculation. 2006;5(3):54–58. (In Russ.)]. eLIBRARY ID: 11845981.

26. Tankanag A, Chemeris N. Application of adaptive wavelet transform for analysis of blood flow oscillations in the human skin. Phys Med Biol. 2008;53:5967–5976. Doi: 10.1088/0031-9155/53/21/005.