Psychological stress during exercise: cardiorespiratory and hormonal responses

Area of Science:

• Exercise Physiology
• Stress Response Research
• Human Performance

Background:

• Understanding the physiological impact of combined stressors is crucial for optimizing training and mitigating health risks.
• Previous research has explored physical and mental stress independently, but their synergistic effects require further investigation.

Purpose of the Study:

• To investigate the cardiorespiratory and stress hormone reactions to a combined physical and mental stressor.
• To compare the physiological responses during a dual stress condition (DSC) versus exercise alone condition (EAC).

Main Methods:

• Eight participants (VO2max = 41.24 ± 6.20 ml kg⁻¹ min⁻¹) underwent two conditions: DSC (cycling at 60% VO2max with a mental challenge) and EAC (cycling only).
• Cardiorespiratory variables (heart rate, ventilation, respiration rate) and stress hormones (norepinephrine, cortisol) were measured.
• Cortisol's area-under-the-curve (AUC) was calculated to assess overall hormonal exposure.

Main Results:

• Significant time interactions showed higher increases in heart rate, ventilation, and respiration rate during the DSC compared to EAC.
• Norepinephrine levels were significantly elevated at the end of the DSC.
• Cortisol AUC was significantly higher during the DSC, indicating a greater overall stress hormone response.

Conclusions:

• Engaging in a mental challenge concurrently with physical exercise intensifies the cardiorespiratory and hormonal stress response.
• This exacerbated stress response, particularly the elevation of norepinephrine and cortisol, may have implications for long-term health, including cardiovascular and metabolic diseases.
• The findings highlight the importance of considering the psychological component during physical exertion to manage overall physiological stress.