Physiological effects of cold air inhalation during exercise

Area of Science:

• Environmental Physiology
• Exercise Physiology
• Respiratory Physiology

Background:

• Cold air may not be fully warmed by the upper respiratory tract.
• Understanding physiological responses to cold air inhalation is crucial for various environments.

Purpose of the Study:

• To investigate the physiological effects of breathing cold air (-35°C) during rest and exercise.
• To determine if cold air impacts oxygen uptake, ventilation, heart rate, blood pressure, and body temperature.

Main Methods:

• Six healthy subjects performed 10-minute trials breathing ambient or cold air.
• Exercise involved cycling at 60% and 75% of VO2 max.
• Physiological parameters including heart rate, ventilation, blood pressure, oxygen uptake, respiration rate, and rectal temperature were monitored.

Main Results:

• Cold air inhalation significantly lowered diastolic blood pressure during exercise.
• Oxygen uptake, respiration rate, and rectal temperature remained unaffected by cold air.
• Heart rate and minute ventilation showed minimal changes during strenuous exercise with cold air.

Conclusions:

• Breathing cold air at -35°C results in only minor physiological changes during rest and moderate-to-strenuous exercise.
• The primary observed effect was a reduction in diastolic blood pressure.
• The respiratory system appears to adequately condition cold air, preventing significant adverse effects on core temperature and gas exchange.