Does Aerobic Capacity Protect Against Stress? Insights From Two Stress-Induction Paradigms

Area of Science:

• Exercise physiology
• Stress research
• Cardiovascular regulation

Background:

• Individuals with higher physical fitness often show reduced physiological stress responses.
• It is not fully understood if this stress-buffering effect varies with different types of stressors.

Purpose of the Study:

• To investigate if aerobic capacity influences psychophysiological stress responses.
• To determine if the stress-buffering effect of fitness differs between psychological and physical stress paradigms.

Main Methods:

• Healthy adults (n=59) underwent two stress tests: Trier Social Stress Test (TSST) and Maastricht Acute Stress Test (MAST).
• Measurements included self-reported stress, salivary hormones (cortisol, cortisone, DHEAS), and cardiac autonomic regulation (heart rate, HRV).
• Aerobic fitness was assessed using peak oxygen uptake (V̇O₂peak).

Main Results:

• Higher aerobic fitness (V̇O₂peak) was significantly associated with lower heart rate during both stress tests.
• No significant associations were found between V̇O₂peak and stress-related hormone levels or other heart rate variability measures.
• The association between aerobic fitness and heart rate did not differ between the TSST and MAST.

Conclusions:

• Aerobic capacity offers a general cardiovascular advantage under acute stress, primarily by reducing heart rate.
• Contrary to hypotheses, this fitness-related cardiovascular modulation was not specific to the type of stressor (psychological vs. physical).
• Higher aerobic fitness may generally mitigate cardiovascular load during stressful events.