Respiratory Muscle Training and Cognitive Function Exercising at Altitude

Area of Science:

• Altitude physiology
• Exercise science
• Cognitive neuroscience

Background:

• High-altitude environments (up to 12,000 ft) can induce hypoxia, leading to hyperventilation and reduced arterial CO2 (Paco2).
• Reduced Paco2 causes cerebral vasoconstriction and local hypoxia, potentially impairing cognitive function and increasing accident risk.
• Voluntary isocapnic hyperventilatory training (VIHT) enhances exercise endurance by reducing ventilation and its energy cost, suggesting potential benefits for altitude adaptation.

Purpose of the Study:

• To investigate the effects of VIHT on executive functions, including working memory and processing speed, at simulated high altitude.
• To compare the efficacy of VIHT against control and placebo groups in maintaining cognitive performance under hypoxic conditions.

Main Methods:

• The study involved three groups: VIHT, control (C), and placebo VIHT (PVIHT).
• Participants underwent simulated altitude exposure up to 12,000 ft.
• Executive functions were assessed using the Stroop Test, Symbol Digit Modalities Test, and Digit Span Forward, alongside physiological measurements.

Main Results:

• The VIHT group demonstrated significant improvements (17-30%) in the Stroop Test, indicating enhanced processing speed and executive control.
• Significant improvements were observed in the VIHT group for correct responses (26%) and number of attempts (24%) on the Symbol Digit Modalities Test.
• Reaction time also improved by 16% in the VIHT group, while the Digit Span Forward test showed no significant changes across any group.

Conclusions:

• VIHT effectively improved processing speed and working memory during simulated high-altitude exercise.
• These findings suggest VIHT may be a viable training strategy to mitigate cognitive impairments at altitude.
• Further research could explore VIHT's role in preventing altitude-related performance decrements and accidents.