The Mannheim Multicomponent Stress Test (MMST) is a validated laboratory stress test that combines cognitive, emotional, acoustic and motivational stress components. However the utility of the MMST as a viable alternative to the more commonly used Trier social stress test (TSST) to elicit HPA reactivity remains unclear as meaningful increases in saliva cortisol (> 2.5 nmol/l) have been shown to occur in <50% of participants yet the TSST typically elicits meaningful increases in saliva cortisol in >70% of participants; likely as a consequence of the greater social evaluative component in the TSST.

Using a randomised between groups design, this study aims to compare psychobiological responses to the MMST and TSST.

Inclusion Criteria:

Participants who…

• have read and signed the study informed consent
• are healthy, recreationally active men and women aged 18-35 years
• are willing to provide saliva samples throughout through the duration of the study
• are using monophasic birth control (women only)

Exclusion Criteria:

Participants who…

• have a recent history or are a current smoker
• are currently taking prescription/Over-the-counter medication (excluding females taking oral combined contraception
• consume ≥ 91 units of alcohol per month
• have a clinically diagnosed history of cardiovascular and/or metabolic disease including diabetes and abnormal blood pressure
• are pregnant
• have a recent or ongoing viral or bacterial illness in past 4 weeks
• have a clinically diagnosed psychiatric disorder
• have a clinically diagnosed sleeping disorder
• have a clinically diagnosed gambling addiction
• BMI ≥ 30 kg/m2 - calculated in the online health screening questionnaire
• Endurance trained or engage in ≥3.5 hours of physical activity a week

Participants will be unaware of the true nature of experimental trials until a final debrief scheduled after acute stress exposure.