Pre-acclimation to altitude in young adults: choosing a hypoxic pattern at sea level which provokes significant haematological adaptations
Author(s)
Tobin, Barbara
Costalat, Guillaume
Renshaw, Gillian MC
Year published
2021
Metadata
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PURPOSE: This single-blind, repeated measures study evaluated adaptive and maladaptive responses to continuous and intermittent hypoxic patterns in young adults. METHODS: Changes in haematological profile, stress and cardiac damage were measured in ten healthy young participants during three phases: (1) breathing normoxic air (baseline); (2) breathing normoxic air via a mask (Sham-controls); (3) breathing intermittent hypoxia (IH) via a mask, mean peripheral oxygen saturation (SpO2) of 85% ~ 70 min of hypoxia. After a 5-month washout period, participants repeated this three-phase protocol with phase, (4) consisting of ...
View more >PURPOSE: This single-blind, repeated measures study evaluated adaptive and maladaptive responses to continuous and intermittent hypoxic patterns in young adults. METHODS: Changes in haematological profile, stress and cardiac damage were measured in ten healthy young participants during three phases: (1) breathing normoxic air (baseline); (2) breathing normoxic air via a mask (Sham-controls); (3) breathing intermittent hypoxia (IH) via a mask, mean peripheral oxygen saturation (SpO2) of 85% ~ 70 min of hypoxia. After a 5-month washout period, participants repeated this three-phase protocol with phase, (4) consisting of continuous hypoxia (CH), mean SpO2 = 85%, ~ 70 min of hypoxia. Measures of the red blood cell count (RBCc), haemoglobin concentration ([Hb]), haematocrit (Hct), percentage of reticulocytes (% Retics), secretory immunoglobulin A (S-IgA), cortisol, cardiac troponin T (cTnT) and the erythropoietic stimulation index (calculated OFF-score) were compared across treatments. RESULTS: Despite identical hypoxic durations at the same fixed SpO2, no significant effects were observed in either CH or Sham-CH control, compared to baseline. While IH and Sham-IH controls demonstrated significant increases in: RBCc; [Hb]; Hct; and the erythropoietic stimulation index. Notably, the % Retics decreased significantly in response to IH (-31.9%) or Sham-IH control (-23.6%), highlighting the importance of including Sham-controls. No difference was observed in S-IgA, cortisol or cTnT. CONCLUSION: The IH but not CH pattern significantly increased key adaptive haematological responses, without maladaptive increases in S-IgA, cortisol or cTnT, indicating that the IH hypoxic pattern would be the best method to boost haematological profiles prior to ascent to altitude.
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View more >PURPOSE: This single-blind, repeated measures study evaluated adaptive and maladaptive responses to continuous and intermittent hypoxic patterns in young adults. METHODS: Changes in haematological profile, stress and cardiac damage were measured in ten healthy young participants during three phases: (1) breathing normoxic air (baseline); (2) breathing normoxic air via a mask (Sham-controls); (3) breathing intermittent hypoxia (IH) via a mask, mean peripheral oxygen saturation (SpO2) of 85% ~ 70 min of hypoxia. After a 5-month washout period, participants repeated this three-phase protocol with phase, (4) consisting of continuous hypoxia (CH), mean SpO2 = 85%, ~ 70 min of hypoxia. Measures of the red blood cell count (RBCc), haemoglobin concentration ([Hb]), haematocrit (Hct), percentage of reticulocytes (% Retics), secretory immunoglobulin A (S-IgA), cortisol, cardiac troponin T (cTnT) and the erythropoietic stimulation index (calculated OFF-score) were compared across treatments. RESULTS: Despite identical hypoxic durations at the same fixed SpO2, no significant effects were observed in either CH or Sham-CH control, compared to baseline. While IH and Sham-IH controls demonstrated significant increases in: RBCc; [Hb]; Hct; and the erythropoietic stimulation index. Notably, the % Retics decreased significantly in response to IH (-31.9%) or Sham-IH control (-23.6%), highlighting the importance of including Sham-controls. No difference was observed in S-IgA, cortisol or cTnT. CONCLUSION: The IH but not CH pattern significantly increased key adaptive haematological responses, without maladaptive increases in S-IgA, cortisol or cTnT, indicating that the IH hypoxic pattern would be the best method to boost haematological profiles prior to ascent to altitude.
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Journal Title
European Journal of Applied Physiology
Note
This publication has been entered in Griffith Research Online as an advanced online version.
Subject
Human biophysics
Sports science and exercise
Continuous hypoxia
Erythropoietic stimulation index (OFF-score)
Haematology
Hypoxic pattern
Intermittent hypoxia