Table 2 Study metrics of stress

• Heart rate or heart rate variability

[25, 27–31, 33–37, 39–45]

• Blood pressure (systolic / diastolic / mean arterial)

[25, 27, 31, 33, 34, 41, 44]

• Skin conductance / skin response

[31, 44]

• Respiration rate

[25, 44]

• Other: temperature [34], oxygen saturation [27], electrocardiogram alterations [36], calories burned [30], capillary lactate [34].

• Saliva:

 cortisol

[7,26 , 27,29 , 32, 41, 43]

 secretory immunoglobulin A

[27, 41]

 testosterone

[27, 41]

 α-amylase

[3838,41]

 Other: dehydroepiandrosterone [29], pH [34], protein levels [41].

Subjective

• State trait anxiety inventory

[7, 26, 28, 31, 34, 37, 38, 41, 43]

• Visual analogue scales of stress and anxiety

[32, 43]

• Perceived stress scale

[42, 44]

• Other: NASA-Task Load Index [26], Subjective scale of distress [42], Life engagement test [42], The coping flexibility scale [42], Framingham type a behaviour scale [42], NEO five-factor inventory [,4242], Dundee stress state questionnaire [44], Cognitive appraisal [7], Motivation [41].

Task performance / clinical outcome

[31, 38]