Optimizing Intermittent Hypoxic-Hyperoxic Training for Safety and Feasibility: An Exploratory Pilot Study

Area of Science:

• Exercise Physiology
• Environmental Medicine
• Sports Science

Background:

• Intermittent Hypoxic-Hyperoxic Training (IHHT) is known to induce physiological adaptations.
• While its athletic performance benefits are debated, IHHT shows promise for improving health in clinical and aging populations.
• This study explored the safety and feasibility of two IHHT protocols.

Purpose of the Study:

• To investigate the safety and feasibility of two distinct IHHT protocols in healthy volunteers.
• To compare physiological responses between a balanced and an unbalanced IHHT protocol.
• To gather preliminary data on cardiorespiratory, inflammatory, oxidative stress, and renal markers.

Main Methods:

• Twelve healthy volunteers underwent a 4-week IHHT intervention (2 sessions/week, 45 min/session) combined with low-intensity exercise.
• Two groups were compared: Training Group (TG) with 30 min hypoxia and Conditioning Group (CG) with 15 min hypoxia.
• Outcomes included cardiorespiratory measures, AMS symptoms, RPE, biochemical markers, inflammation, oxidative stress, and renal function.

Main Results:

• Both IHHT protocols were safe and feasible.
• The TG experienced significantly greater oxygen desaturation than the CG (p=0.048).
• The CG showed a significantly lower increase in Interleukin-6 (p=0.021) compared to the TG, indicating reduced inflammation.

Conclusions:

• A balanced IHHT protocol (CG) demonstrated superior acute physiological tolerability compared to an unbalanced protocol (TG).
• The balanced protocol attenuated cardiovascular strain and mitigated systemic pro-inflammatory responses.
• Preliminary lipid parameter variations suggest potential benefits warranting further research.