Table 2.

Characteristics of devices used to measure physiological stress

Measure	Device	Characteristics
Heart rate variability	Thin elasticated heart rate transmitter belt placed around the chest	Can detect heart rates of 25–240 beats per minute and respiratory rates of 3–70 breaths per minute
Skin conductance	Wristwatch placed around the wrist at the same time as the thin heart rate transmitter belt	Measures skin conductance in microsiemens, 64 Hz frequency and movements with a triaxial accelerometer
Stress biomarkers	Salivette. A synthetic cotton swab is removed from the Salivette and placed in the mouth of the participant to chew for about 1 min	The Salivette is stored at −80°C and then sent to a laboratory for analysis